How rapidly can we transition to 100% renewable electricity?

Print Friendly, PDF & Email

Science tells us that, to avoid devastating climate change, we must rapidly cut greenhouse gas emissions to zero. How fast is possible?

This article focuses on the transition of the electricity industry to 100% renewable electricity together with energy efficiency, for the following reasons:

  1. energy generation is the major contributor to emissions;
  2. energy efficiency together with renewable energy form the cheapest, safest and cleanest combination of energy technologies; and
  3. a renewable energy future is likely to be based mostly on renewable electricity, because electricity is the least difficult form of energy to transition.

So far two extreme viewpoints have characterised the debate. On one hand, the ground-breaking Zero Carbon Stationary Energy Plan set a decadal transition as its aspirational target.

However, the argument that this is possible appears to be based on two general points – Australia’s huge renewable energy and raw material resources, which no-one would deny, and the belief that Australia’s manufacturing industry has the capacity.

While the report was strong and detailed on technological hardware, there was no analysis of the time needed to train the workforce, which is already overstretched by the growth of renewable energy.

It would take at least a decade to train just the first cohort of engineers and give them essential experience. Amateurs cannot design a manufacturing process or connect a wind or solar form to the grid.

Furthermore, the report didn’t address the challenge of rebuilding our declining manufacturing industry, or the long time it takes to build transmission lines, or the impact on energy prices of a rapid transition. So a decadal transition is unproven and unlikely.

At the other extreme, Vaclav Smil, an expert on historical energy transitions, argues in his book that ‘the process of restructuring the modern high-energy industrial and postindustrial civilization on the basis of nonfossil, that is, overwhelmingly renewable, energy flows will be much more challenging that [sic] was replacing wood by coal and then coal by hydrocarbons.’

To question Smil’s conclusions it’s sufficient to refute the assumptions underlying his key arguments.

A more extensive critique, in Section 6 of our recent peer-reviewed paper ‘The feasibility of 100% renewable electricity’, is available free upon request from [email protected]

One of Smil’s key arguments is that beliefs in the possibility of a rapid transition are inadequate because they are based on transitioning electricity alone.

Smil appears to be unaware that most scenarios for 100% renewable energy involve transitioning almost all transport and non-electrical heat to renewable electricity.

The main exceptions are long-distance rural road and air transport, which will need renewable fuels.

Smil seems to be under the incorrect impression that we must focus on changing the fossil fuel primary energy inputs – coal, oil and gas – to renewable energy, presumably because the traditional energy flow diagram (see figure) starts with primary energy on the left, then flows through transformation processes (e.g. combustion in a power station) in the middle of the diagram – to provide on the right-hand-side, after substantial energy losses, the end-use energy and hence the energy services we demand: a warm home in winter, hot showers and cold beer.

This puts the cart before the horse.

However, if we start by considering what energy services we really need, we can integrate energy efficiency and conservation with renewable electricity, thus reducing the demand for end-use energy, which will be used mostly as electricity.

Then, when we reduce electricity use by a certain amount, we substitute for approximately three times that amount of energy in primary fossil fuels used for electricity generation.

This is because of the low efficiency of conversion of fossil fuels into electricity, as illustrated. A strategy that moves from right to left is much easier than the opposite.

Smil also asserts that the successful transition of a few countries is irrelevant to a global transition. Presumably he thinks that the rapid ongoing transition of Denmark, with 44% of its electricity in 2017 coming from variable RElec (wind), and Germany with 26%, are special cases.

However, we can also consider the north German states of Schleswig-Holstein and Mecklenburg-Vorpommern (100% net, mostly wind), South Australia (45%, wind + solar PV), Scotland (44% of consumption and over 60% of generation, mostly wind) and several states of the USA (each with 25-30%).

These successful examples are relevant as the pathfinders for other regions, demonstrating how reliability, security, affordability and environmental sustainability can be achieved with high and increasing contributions from variable renewable electricity.

They also continue to drive down the costs of renewable technologies for the rest of the world, which then experiences an easier transition than the pathfinders. Germany’s success in driving the market for solar PV, and so bringing down its costs, brought China into manufacturing PV, resulting in further reductions in costs.

Thus the successful examples are relevant both as symbols and in practice.

To achieve 100% renewable electricity, wind and solar power must be scaled up. Smil assumes incorrectly that this can only be done by increasing the size of wind turbines and their efficiency of conversion to impossible levels.

This overlooks the fact that wind and solar technologies (and batteries) are mass-produced in factories and so the principal increase in capacity and reduction in cost comes from rapidly producing more wind turbines and solar modules to meet the demand of an expanding market, and from improving supply chains.

Bigger, more efficient wind turbines and solar modules play a role in the scale-up, but it’s a minor one.

Because Smil’s assumptions are questionable to say the least, his argument that the transition to renewable electricity will take longer than historical energy transitions, is poorly based.

On the other hand, the facts that wind turbines, solar PV, CST, batteries and energy efficiency technologies can be mass produced rapidly and are less expensive per unit of electricity generated or saved than new fossil fueled and nuclear power stations, gives confidence that a rapid transition is technically and economically possible.

A future article will propose a transition scenario that’s much faster than Smil’s, but doesn’t assume the unrealistic decade.

Dr Mark Diesendorf is Education Program Leader (part-time)  at the Cooperative Research Centre for Low Carbon Living at UNSW.


  • Chris Drongers

    What about the argument (and i am hyper-extending the original concept) that the transition to renewable energy will require so much energy (from fossil fuels) and other resources (iron, aluminium, copper, glass) that it will destroy the climate before reducing CO2 emissions by the required amount?
    Wouldn’t we be better off covering large areas of mid latitude deserts with aluminised 100 micron Mylar mirrors to reject the extra heat load?

    • john

      Is that going to come back as heat the same?
      Is it long range or short range ?

      • Chris Drongers

        Absorbing sunsnine into mass (heating soil, water or air) or into latent heat of vaporisation by evaporation from vegetation is the climate problem we have now. Reflecting shortwave (largely visible light) back into space before it is absorbed and re-radiated as loner wave infra red radiation that is absorbed by CO2 was the idea behund the mirrors.
        The problem with making enough renewables to reduce co2 emission is not full lifecycle eroi but the shortterm imbalance as massive amounts of pv and windmills are built requiring so much energy that we’re all ruibed before the payback occurs. Are we in ‘coffin corner’? Ruined whatever we do?

        • john

          No Chris if we build Solar and Wind which are driven by incoming solar energy after all as well as PHES which once again is driven by incoming Solar Energy we are harvesting the energy delivered to the planet.
          Net mitigation of incoming energy not transmitted IMHO.

        • john

          The energy required to build a wind farm or a solar plant yes is large however is it not paid back in a short time from faulty memory about 5 years possibly wrong. Regardless from then on is energy beneficial.

          • Mark Diesendorf

            The energy required to build a wind farm is paid back in energy terms in less than one year. For solar farms its 1-2 years and decreasing. Of course the results depend upon the site: at a very good site the payback period is short than at a moderately good site.

          • john

            Thank you Mark and I will take your word on this as you do have some training in the area I was deliberately moderate in my estimation.

          • Rod

            A contributor from another forum provided this. For the metal portion of a wind turbine.

            One of the highest energy requirements is for the steel used in
            the turbine, tower and reinforcing. He indicated 260 tonnes.

            “Steel is so easily recycled. And steel hasn’t needed coke
            for production since the 40’s. It fit for traditional steelmaking but new
            steelmaking plant easily and economically work without. Actually making better

            Liberty House’s Whyalla steelworks is going to use large amounts
            of recycled steel in their process.

            But to help you, I’ll assume no recycled steel:

            “On average, 20 GJ of energy is consumed per tonne of crude
            steel produced globally” (worldsteel org raw-materials)

            20GJ is 5.56MWh,

            260 tonnes of steel then needing 5,200GJ = 1,444.44MWh.

            For a 3MW turbine at a low 35% capacity factor,

            1,444.44/(3 x 0.35) = 1,375.66 hours.

            Under 57 days, 7 hours, 40 minutes or done before 25 Dec 2017,
            ready for xmas if we commissioned the turbine today.

          • MacNordic

            This report covers the energy payback (and plenty of other stuff) quite exhaustively – please refer to page 38:


            Note that the insolation in Germany is around 1055kWh/m²/a or less. Australia has between 1500 and 3000kWh/m²/a, if you exclude Tasmania, which – even at the low end – gives an energy payback time of around one year.

        • Peter F

          According to Siemens and GE a windfarm on a good site has a 3-5 month energy payback. If it is displacing old coal with a system wide efficiency (including mining, maintenance and waste disposal) of 25% then in effect the CO2 emissions involved in manufacture are recovered in around a month.
          If we were serious and put 5% of the world’s copper production into wind turbines, you could build about 3.6 TW of wind turbines producing about 13,000 TWh of electricity every year, the world only uses about 165,000 TWh of electricity of which about 30% is already produced by nuclear and renewables. Total end point energy use is about 250-300,000 TWh so diverting 5% of total copper production to wind energy could have half the worlds energy use supplied by wind in about 20 years

    • Alastair Leith

      Well if you are making that argument you’d better advance some life-cycle analysis to back it up. PV became EROEI positive during the Apollo missions. Wind is also EROEI positive. EROEI is rabbit hole of a discussion when it’s done with any nuance, and is partly why these myths still circulate, and partly because some people like to believe they are true for reasons best known to them and their analyst.

    • Alastair Leith

      Wow mirrors, you think their won’t be any conversion to IR radiation and GHG won’t trap that energy? better to absorb it as energy with vegetation or solar energy. Mind you mirrors in space if we had the tech and resources could be interesting.

      • john

        Putting mirrors to cover a 1/20 earth to reduce incoming energy would cost about the total GDP of earth by 20 times a WAG.
        In other words a huge recession. Not going to happen.

        • Alastair Leith

          Exactly, would require a raft of major tech breakthroughs that are essentially science fiction.

        • Alastair Leith


          • john

            Wild Ass Guess
            in other words wrong

          • Chris Drongers

            Earth surface area 510072000 km2, radiative forcing from memory is about 1Watt/m2 so 0.1% of Earth surface needs to be under mirrors, double for reabsorbtion of reflection, off angle and general loss, so need about 1M square km of mirrors (10^12m2) , Alibaba is selling aluminized Mylar at $1.50/kg, aboutv10m2, so $0.15 * 10^12=$1.5 * 10^11 or $150Bn to save the planet, or equivalent of 15 nuclear power stations or 50 coal power stations.
            Not so much as to be undoable

          • john

            Yes perhaps.
            So the mirrows will not be reflected back to earth exactly as the GHG’s do?
            Not all reflected energy reflected to the air comes back but enough does to as you know raise the average temperature on earth over 100 years the same as used to happen over 10,0000 years.

            I agree doable but is it a good idea?

          • Alastair Leith

            I have a couple of rolls of Mylar to donate to get this project started, Chris.

    • john

      The energy into producing Re Solar or Wind is paid back in a short time.

    • Mark Diesendorf

      Chris, my colleagues and I at UNSW have researched the life-cycle CO2 emissions emitted by mining the materials and building the renewable energy technologies from transitioning to 100% renewable electrciity. The good news is that these emissions are small compared with the emissions saved by substituting renewable electricity for fossil electricity, see (I think the article was reprinted in RenewEconomy.) As the transition proceeds, renewable energy technologies are made increasingly with renewable energy.

    • Peter F

      The argument may have had some validity years ago, but now it is completely silly now. a 3.6 MW wind turbine has a tower that weighs about 250-350 tonnes and a Nacelle and rotor that weighs 250 tonnes and a foundation of about 600 tonnes. If we have energy services equivalent to 500 TWh all from wind we would need about 36,000 wind turbines, (the US already has 58,000) The turbines would contain about 500 tonnes of steel each and 450 tonnes of concrete. so over a 15-20 year period we would need a total about 20 m tonnes of steel and 15 m tonnes of concrete, 2.5 m tonnes of glass fibre and insulation and probably 500,000 tonnes of copper. At the peak of the domestic car and appliance industry those two industries used about 1 m tonnes of steel between them, we still use about 6m tonnes per year in total so a completely unrealistic wind based energy transition would still only account for 15-20% of our steel consumption . As for concrete Australia uses about 150 m tonnes per year. We produce a bit under a million tonnes of copper so those materials are again trivial

      • Jens Stubbe

        Wind power completely dropped REE over very few years. Now copper is going the same route.

        A 2.3MW Vestas offshore turbine 10 years ago had a nacelle weight only slightly less than their 10MW turbine today and far less capacity factor.

        Despite the square cube rule the engineers have been able to use ever less materials for ever more AEP. This is not about to change.

        This year Hempel launched their new coating for marine surface that is guaranteed for x3 longer periode so the turbines for offshore are soon likely to be good for more design life – maybe double og triple, which will improve bankability and overall LCOE.

      • Ertimus J Waffle

        Where are you going to put the 38,000 wind turbines and how many more replacement turbines would have to be built every year to replace the worn out ones with an average life span of 10 years. With so much capital invested what would be the final number of turbines needed and their cost. Coal fired power stations capital and running costs were all identical the only difference was the replacement power station had twice the generating capacity and the fuel cost was only 10 to 20 percent more with all power stations having a 40 year life span.

        • Peter F

          We don’t need 38,000 wind turbines. For wind to supply 50% of electricity demand, at current demand + displacing 70% of gas for domestic heating, hot water and 70% of transport we need to supply about 270-300 TWh of electricity, 50% of that will be roughly 145 TWh. New onshore wind turbines supply 12-20 GWh. (The Halliade X which can be established in shallow waters near Sale and in the Gulf in SA is expected to generate 65 GWh per turbine).

          Just using currently marketed onshore machines with an average of 13 GWh we need 11,000 (38,000 MW) spread over about 1.6 m sq km of 66 kV+ grid. Scotland in 75,000 square km has 6,000, Germany in 350,000 square km has 24,000. Oklahoma already has 7 GW of wind in 180,000 square km and is building more, one plant alone currently progressing through approval is 2,000 MW so by 2021 Oklahoma will have about 60 kW of wind capacity per square km. If we did that just within our existing grid we would have 110,000 MW of wind power enough to supply about double our total energy use, not counting solar, hydro etc etc.

          As for replacements: In fact there are 10s of thousands of 20 year old wind turbines still operating, even the very first offshore wind farm lasted 20 years and the technology has improved a bit since. So using a realistic figure of 25 years life for modern wind turbines and allowing 2% per year increase in annual output due to improved designs, by 2050 we will need to be replacing about 1,500 MW or 450 old turbines per year. They will be replaced by 260 new ones i.e. less than the current rate of installations

  • Peter F

    We already have the capability to commission about 600 wind turbines/year which we will average this year and next. It is quite easy to add 15-20% per year to the build out rate
    Those farms already completed or in construction over 2018 and 2019 will deliver about 14 TWh New wind turbines are gradually increasing in capacity factor and size so if we allow a 1% per year increase in capacity factor and 2% increase in size and 15% increase in number of turbines, by 2020 8.5 TWh/y per can be added from wind increasing at 18-20% per year. That means by 2025 there would be an additional 90-100 TWh of wind from the start of this year. If you think that is hard, Scotland is installing one wind turbine a day and its economy is roughly half that of NSW

    It also appears we are quite capable of building 1.5 GW of rooftop solar and an equivalent quantity of utility solar per year. That will provide about 5.5 TWh. Using a 15%/y growth rate between the start of this year and the end of 2025 that is another 75 TWh or a total of 160-175 TWh from wind and solar.
    Throw in solar thermal, waste to energy, a dozen or two biomass plants and you are heating to 200 TWh from renewables by 2025-2026,Currently coal and gas only provide 160 TWh to the NEM so a seven year transition on business as usual is not too difficult.

    Now of course we want to electrify heating and transport as quickly as possible so putting in 40,000 electric busses and 10% more suburban trains and trams and say 500,000 electrified light vehicles and 5 million heat pumps for heating and 1.5 million heat pump hot water services will add back about 6 to 8 TWh, so in essence if we wanted to continuing at more or less business as usual we can eliminate 90% of electricity emissions and 30% of heating/hot water

    Of course if our economy was as energy efficient as Spain or California even allowing for population growth we could eliminate at least another 15-30% of energy consumption as well

    • gasdive

      I was scrolling down to say much the same but you said it better. I’d also point out that there’s a lot of unused human potential in terms of electrical infrastructure. The on again, of again nature of infrastructure investment means there are a lot of good people doing other things that could be coaxed back.

    • solarguy

      I agree 99% of what you have written. Leave out the hot water heat pumps and use evacuated tube solar hot water, you can add more than 6-8TWh.

      • Peter F

        I agree and we could add in many more opportunities, 2 solar panels on a roof running a heat pump hot water service only produce about 10 GJ of primary energy/day but produce about 200 L of hot water. Accounting for mining and operation and transmission losses an old coal plant powering an immersion heater needs to use 110 GJ worth of coal to produce the same energy services to use Mark Diesendorf’s very apposite term. Similar numbers can be achieved with well designed space heating/cooling and lighting.
        New York state is aiming for 3% energy efficiency gain per year and we are less efficient than they are even now, i.e. we .

        • solarguy

          Gee Peter, You don’t think that 2 PV panels will run a hpump do you, because if you do, you are incorrect.

          Please talk in kwh not joules.

          • Peter F

            I am sorry if my maths is wrong but it goes like this. Solar panels in most of Australia produce 5 kWhr/kW/day so two 300 W panels produce 3 kWh per day. 200 L of hot water heated by 40 C is 9.1 kWh allowing for inefficiency say 10 kWh with a COP of 4 that is 2.5 kWh i.e < two 300 W panels. Sanden is saying COP of 5 with latest models so that would actually only need 2 kWh. Having said that I realise that heat pumps are usually rated at 500-900 We so a bigger unit would need 4-5 panels to run at full power but only use 40-60% of the daily production of the solar panels

          • solarguy

            Quite incorrect assumptions I’m afraid. Firstly 1kw of PV may at times produce 5 kwh/day may even produce more, it depends on the time of year and the weather conditions amongst other things, so this varies. Now as a rule of thumb the highest average daily output of 1kw of PV may produce in the right conditions ( sunny partly cloudy day) 3.9kwh.

            Another way of thinking about it is 3.9 Peak Sun Hours (PSH)
            So 600 watts x 3.9PSH = 2.34kwh. However as conditions aren’t static you may only achieve 0.65 PSH on certain overcast days. Now let’s talk about max power of a 300w panel at NOCT at around solar noon. That 300w rating is at STC measured at the factory, but you won’t get STC often, in fact NOCT is where it’s at and you will only get 221w x 2 panels only gives you 442watts, and only for an hour either side of noon, ummm! And that’s before losses in cable and inverter efficientcy. Note: To heat 180lt of water from 15c to 60c requires 9.5kwh

            Sanden heat pumps are very good, but look a bit deeper and you will find you won’t get COP of 5, but more like 4-4.5 from memory and that will be at 20c ambient temp, go lower in temp, COP can go as low as 2. And that compressor uses up to 1200watts, NOT LOOKING FEASIBLE to run it on 2 x 300w panels is it! So on a good day to run that heat pump you would need much more PV, like about a 1.5kw array. But that won’t do the business on a shitty day.

            An resistive element is usually 3.6kw so that other theory is shot to flames also. If you want to heat water reliably and cheaply an evacuated tube system is the way to go. In fact my system has not needed any grid power for 18 months or any PV for that matter. Now tell me that isn’t cheap and the collector takes up half the space as PV would.

            Facts not fiction!

          • Peter F

            I don’t think you read my reply properly, In fact I think you are partially confusing power with energy.
            I did concede that you need more panels for both installations but the extra panels means that on most days you will have power to export, you can’t export excess solar thermal in summer.
            While an immersion heater can draw 3.6 kW it doesn’t need to to heat the water. Using your figure it needs 9.5 kWh/day. Even at 4 kWh/kW/day eight 300 W panels does the job, if they are DC coupled or through a PWM power supply to maintain optimum voltage, losses are negligible. If you buy a larger tank and super heat it and fit it with a mixing valve just like your solar thermal system 400L of hot water can last 3-4 days even if solar output on one day is down 90%

            I am not against solar thermal nor am I particularly in favour of heat pumps I think they are in some cases unnecessarily complicated.
            The main point of my original post was to show that primary energy use can be a very misleading term. You can get the same quantity of hot water for approximately 1/10th of the primary energy, the same with well designed lighting and transport systems.
            In summary my post was about energy consumption not instantaneous power levels and it was factual.

          • solarguy

            No not confusing power with energy. You still don’t get it, sure you can use a diverter to get that element to work by giving the voltage that’s required and on a good day produce 9.6kwh and job done. But that is just for 180lt to 60c and the roof area required is higher than a E.T. SHW collector and diverters aren’t cheap. A heat pump is better use of the energy owing to the COP of 4, but only at 20c ambient. It works out to be more expensive than a SHW system. Plus the E.T.SHW system doesn’t loose efficiency at low temps, as long as you have enough solar radiation it will get the job done.

            You use the term “super heat” but do you understand what that means?

            Love to hear the explanation for heating water with only 1/10th the energy.

          • Peter F

            Let me explain. I am a mechanical engineer with most of my work involving electrical components with PWM power supplies of various sorts so I do understand the difference between power and energy.
            Let me put it another way for you, if you add three extra solar panels to an existing rooftop solar system, which I agree will take up more space than a direct solar heater, the extra energy generated per average day in most of Australia will be about 4-5.5 kWh, clearly less in winter more in summer. If you also install a heatpump hot water system heat requirement will average 9-10 kWh/day divided by the COP somewhere between 2.5 and 5 depending on the brand and ambient temperature. That means you need between 2 and 4 kWh per day for a heatpump which as I said can clearly be supplied on an annual basis and in fact on about 9 out of 10 days.
            The advantage of using solar PV is that on 8 out of 10 days the extra solar extra electricity can be used in other ways or sold. For about half the year the solar hot water system collects heat that is just wasted. If you go away for a couple of weeks the solar PV system will make you a bit of money every day and reduce emissions from other customer, the solar hot water system does nothing.

            As for solar PV connected to an immersion heater While I know internet price searching is not necessarily accurate it is quite common to build a solar system with 6kW of panels and a 5 kW inverter for about $5,000, adding another 3kW of panels (if you have the roof space), a diverter and a 400L hot water system is about the same cost as a good quality 400L evacuated tube system. The advantage is that on average the solar system will generate about 5 kWh surplus per day that can be exported or used internally at an average value of about 15 c so in addition to hot water your electricity bill is reduced by $250-300 per year

            As for superheat just as your solar thermal hot water system occasionally gets to 80-90 C and even higher that means that you fit it with a mixing valve to mix down the hot water to 48C so when you draw off hot water at say 85C and mix it with cold at 15C you actually send out a mix of roughly 50/50 cold/hot water so in effect a 400L hot water system becomes a 600+L system i.e. provides 3 days hot water with zero reheating. If you had 5 days where the solar PV could only provide 1/5 of its average output you still don’t run out of hot water.

            Finally as I said to produce 10 kWh of heat in an immersion heater including the energy used in mining, transporting and processing coal and handling waste and cooling water + the losses in the T&D system a typical Australian coal plant would need between 35 and 55 kWh worth of coal in the ground. A heat pump hot water service needs between 2 and 4 kWh from a solar PV system on the roof i.e. the primary energy required could be as little as 4% of that from an old plant like Hazlewood to produce the same amount of hot water and usually less than 10%.
            I am sorry if my explanations are a little bit complicated but equally please read what I am saying rather than what you think I might be saying

          • solarguy

            You’re a mechanical engineer, but you are not an accredited PV system designer, like myself. I have already explained to you, but you have failed to understand what power you will get out of a 300w PV panel, but I will partly repeat it just one more time.

            A 300w panel will only produce 221w at NOCT, disregarding any further losses for a moment, 3 such panels, will only produce 663w a good deal short of the 900w the heat pump compressor motor needs and that’s if it only requires 900w a Sanden will need 1200w, if it can’t get the power it needs, it will have to come from somewhere else like the grid or the existing PV system that you never mentioned before, which means other loads in the house may have short a fall, so where does that power come from if there is a short fall then, oh I know the bloody grid.

            Now even if you get the PV power needs correct for said hpump under good conditions and you will only get that for an hour either side of noon. Has the penny dropped yet?
            In comparison a SHW isn’t fussed if the power drops off for whatever reason it will continue to add heat to the tank, like a battery! BTW SHW doesn’t go as high as 90c for domestic 80c max and super heated water is 100-374c. FYI, I sell SHW as well apart from owning one, have been selling them for 10yrs. I know about thermostatic mixing valves old son, strangely enough.

            Out of 365 days you will not get 9 out of ten days that will produce enough power to run the compressor motor even if you oversize the PV. If you have a battery of the right size, then kwh produced will come into the equation, but even then it won’t be the whole story sorted, as we get plenty of cloudy, partly cloudy and overcast/ rainy days. I haven’t needed to boost my SHW for 18months, until just recently. For the last 15 months my hybrid system has enabled us to be self sufficient for electricity, but we couldn’t have achieved that with a bloody h/pump stealing power for our hot water.

            Talking of primary energy, it could be reduced even more if homes a better designed and we use E.T. SHW instead of PV powered hot water from any other technology.

    • Ian

      What a breath-taking summary. Let’s hope this transition rollercoasts as fast as your description!

    • Ertimus J Waffle

      Where are you going to put the 600 new wind generators and how are you going to transmit the power to the load centers???? Talks cheap, engineering is expensive.

      • Mike Westerman

        So despite your inane posts you are an engineer?

        In case you hadn’t noticed there are way more than 600 wind generators being installed at the moment…

      • Peter F

        Along the existing grid. Scotland has 6,000 wind turbines in 80,000 square km. The US has 55,000 wind turbines in about 4,500,000 square km of grid served area, Germany has 24,000 in 350,000 square km. The NEM covers about 1.2 m square km and because of superior wind resources and newer technology we will only need about 7-8,000 wind turbines in a 90% renewable grid.

        The densest energy use in Australia is the coastal strip from North of Newcastle to south of Woolongong, and stretching about 200 km inland to include Canberra. That area uses about 1,200 MWh per square km per year for all energy needs. Germany already generates 650 MWh/square km/year and plans to double it. Because of superior wind and solar resource, newer technology and greater land availability we will be able to double the German energy production per square km. In other words in that 130,000 square km we could generate about 260 TWh. The total energy services in that area including transport and efficient heating other than a few high temperature processes like steel making is about 120-150 TWh i.e. NSW can generate almost double the projected energy use all within 200 km of the load.

        The engineering has been examined and the strengthening of transmission and increase in grid based storage (but not including the actual generation) can all be done for about the cost of a single 2 GW coal plant.

        According to the NREL California can generate 73% of its power from rooftop solar at 16% panel efficiency. As panels are now available with 20%+ efficiency if NSW used solar canopies on carparks as well as covering all the suitable unshaded North and West facing roofs i.e. about 22% of its roof-space, it could generate 90% of its electrical demand just from behind the meter solar

  • john

    For every Solar Farm built in the latitudes that are conductive to producing the best outcomes a 1 MW Solar Farm will produce 4 times or better it’s size.
    Yes only during the day so back it up with Wind and PHES as well as Battery Storage this is a no brainer.

  • Alastair Leith

    Regards liquid fuels for aircraft and long haul transport, someone at NASA (I forget who now) once said for commercial scale aircraft 100 passengers and above, an energy density of 700 Wh/kg is required. Tesla Model 3 I think is estimated to be using a battery with something around 167 Wh/kg but people who have toured the plant claim there’s a battery in a glass case Tesla show off that is purportedly 200+ Wh/kg. That and higher are happening in labs various places but yet to make it across the valley of death.

    I’ve seen people quoting Elon Musk saying he wants 300-400 Wh/kg for “jets” by which I think he’d be talking smaller than 100 passenger high speed, high altitude aircraft that could match a Learjet in performance characteristics (and smash on fuel costs presumably).

    I wouldn’t be so quick to say 700 Wh/kg batteries will not happen before the current fleet of aircraft are converted to sustainably fuelled (zero net emissions) jet turbine aircraft.

    • john

      It will happen just watch the information.
      Every week there is advancement.
      As you know do not expect anything on Fox News.
      Just cast your mind back to the memory chips we had I got the best in 1981,
      8 kbs of memory what does your phone have now? 30 GBs
      Tells a story does it not.

      • RobertO

        Hi John, and both power consumption and battery have become much smaller and lighter in weight yet they are longer lasting.

    • Mark Diesendorf

      For aircraft carrying hundreds of passengers or a heavy cargo load, forget about batteries. These aircraft will need renewable fuels, e.g. hydrogen produced by electrolysis of water, or ammonia produced by combining renewable hydrogen with nitrogen from the air. At present these renewable fuels cannot be produced efficiently and so they are expensive, however this may change in the medium-term future.

      • john

        For short distance travel perhaps will work once they meet the requirements IE enough energy to go to alternate airport etc see my other post on this subject.

        • Mark Diesendorf

          Short-distance (less than about 1000 km) intercity passenger travel on the ground can be done rapidly and in comfort by high-speed rail. Unfortunately it seems politically impossible in a rich country, Australia, to link Melbourne, Canberra, Sydney and Brisbane in this way.

          • Alastair Leith

            HSR for the win certainly. Hyperloop one day I hope. 🙂 I accessional daydream about sci-fi kind of way to put HSR rail across the oceans at an affordable price… aircraft will dominate that space and ground travel where mountains are in the way for decades I suspect.

          • Mike Westerman

            The Norwegians are building an undersea floating car tunnel, so i can see why it couldn’t also take trains. Only shallow seas tho to keep cable tethering to reasonable length.

          • Alastair Leith

            Wow, thanks for tell me Mike, I’ve often wondered about some kind of just under water rail line that could rise to the surface as the train passed over it then submerge again to get out of the way of boats etc. I don’t know how you’d stop whales hitting a submerged tunnel :- Yeah I was thinking deep ocean really, b/c thats the big aircraft commute routes.

          • Mike Westerman

            I think the article was on LinkedIn but try Googling it – it stays fixed in place about 20m below the surface to allow ships to pass above and also put enough tension in the anchors to be stable. So I guess whales would learn it was there – whether they’d like it and not head butt it is another question!

            But Australia needs to get HSR between Syd-Mel-Bne first!

          • Peter F

            There is a strong argument that there is so much embodied energy in high speed rail lines with their necessarily large curves, bridges, tunnels etc that unless you are running 40-80 trains a day, it is more energy efficient to fly

          • Alastair Leith

            I’d want to see the math, av-gas is a big emissions source that isn’t properly accounted for by standard UNFCCC/IPCC accounting methodology,

          • solarguy

            Perhaps think more of reginal destinations where aircraft are needed.

      • Jens Stubbe

        Mark I think you are too pessimistic about electric propulsion in air. It is absolutely doable to electrify aviation.

        I agree a smart option is ammonia metal pellets and fuel cells as this is standard commercial products with the required power density.

        Water vapor release in aviation commute heights is a no go from a GHG perspective so either they have to carry the water or they have to produce ice that can be dropped continuously.

        However this hybrid solution too will require massive batteries as the fuel cells cannot deliver the needed thrust for fast rise.

        The break even point for electrolysis based Synfuels based on RE is very close. Based on past experience this will happen around 2025 and mind you that will be against heavily subsidized US Fracking gas and fully depreciated steam reform power plants.

      • Alastair Leith

        Airbus have their E-fan X project due to test fly a – 2MW – electric fan in 2020. Then they will replace a second of the three conventional motors with another electric fan. Airbus will power it from an onboard Rolls Royce AE1107C gas-fueled turbine designed for shaft power not jet propulsion and used in the Ospreys. The generator is onboard the aircraft inside the fuselage, driving 3x 1 MW Honeywell generators (to generate electric power). Hydrogen is going to have to come a long way to power it. They also have batteries onboard to boost power output (for takeoff as Jens notes) and do more quite and fuel-free descents.

        It’s not beyond possible that batteries become an option, but a long way to go obviously, the theoretical limits of lithium ion as I understand it to be is ~3000 Wh/kg but nothing reported above 300 Wh/kg yet in the labs. Other battery chemistries using more commonly available and affordable compounds as material inputs have a significantly higher theoretical limit than lithium ion batteries too. I don’t see why Hydrogen is the only bet to be placing at all. Sure it has energy density, but inefficiencies too in the production and transportation, especially if it’s going to be burnt as fuel.

        • Jens Stubbe

          RE based hydrogen will overtake FF hydrogen very shortly. Would have already if there were such thing as a level playing field. Safety is a big concern in aviation so that hydrogen has to be stored safely. The most elegant method is developed by Amminex, which is now French owned. They store ammonia in metal pellets that are fire proof up to 400 degrees Celsius. The pellets are reusable. The problem is that in so far is more expensive than jet fuel. But again jet fuel does not pay for the environmental issues it causes.

          • Alastair Leith

            How about issues handling the ammonia, worker safety?

          • Jens Stubbe

            The Amminex pellets have a thin coating and you can hold them in your hand as they are dry. They are invented by Claus Hviid Christensen who was the CTO of Topsoe (number one in industrial catalysts), professor at DTU and CEO of LORC (Lindoe Offshore Renewable Center where the offshore wind power industry was developed and the nacelles from both Siemens and MHI Vestas are still built and the next gen offshore is being developed).

            Interestingly the MHI Vestas 164 development cost was about 1/35 of the development cost of the Airbus A380.

          • Alastair Leith

            Someone told me the other day ‘airline tax’ amounts to multiplying the price of any given product readily available in another industry by ten if it’s to be used in an aircraft.

          • Jens Stubbe

            Safety safety safety. It cost but the alternative is unacceptable. Now increasingly the GHG effect is unacceptable as well as noise and toxic pollution so the design demands are mounting in aviation.

          • Alastair Leith

            So ammonia is never hits the air once in the pellets? Ingenious, indeed. How are the pellets opened to get the fuel out?

          • Jens Stubbe


            At the front page a person is holding a lump of the material. The release system is a small induction oven basically.

      • Alastair Leith

        Jetex To Get Charge Out of Wright Electric Partnership

        WRIGHT WEPORT APRIL 2018 Hydrogen and battery powered flight discussed. The Jetex | Wright Electric partnership is about battery powered electric flight. If this is today’s shorter goal, long haul passenger and cargo will come… most technology scales until fundamental physics limits are reached.

      • solarguy

        There is the air ship alternative for heavy cargo. I saw on Discovery channel a few times a lighter than air craft with a non traditional shape, wide and deep. One could imagine such a design covered in thin film PV. It could fly at altitudes above any cloud cover and use the battery at night, albeit at slower speed than during day.

        Way faster than ocean going vessels and cheaper to boot.

    • Jens Stubbe

      700 Wh/kg is probably for entry level in short commute planes.

      A dreamliner carries up to 161 tonnes of fuels. The engine weighs 24 tonnes and the reinforcement to carry engines and tanks in the wings weighs another 24 tonnes roughly. Those 205 tonnes is what you can replace by batteries and multiple small lightweight electric motors.

      At the peak efficiency the dreamliner jet motors delivers 36.1% efficiency but on average tops 30% so a battery driven electric motor is a factor 3 better.

      Jetfuel contains 10.000 Wh/kg so a Dreamliner carries no less than 1.610.000.000 Wh and can deliver a useful 483.000.000 Wh.

      The bulky motors and their suboptimal location from an aerodynamic point of view combined with the option to redesign the entire plane should deliver a factor two better energy efficiency per seat. (Avoid flaps, avoid rudders, wider body, wider wings, decrease frontal area, improve aerodynamics, fast rise (jet motors are lousy at rising the plane so take off and rise is very power consuming relative to electric motors where they is no power penalty for going full throttle) etc.)

      I do not put the weight of electric motors into the equation because I also dropped the on board electricity consumption for keeping the plane pressurized and heated etc. which will use more fuel than what electric motors weighs.

      So you need to deliver 241.500.000 Wh that can at tops weigh in at 205 tonnes. The loss factors in electric transmission will be about 10% so you could start making Dreamliners with the same reach and speed with 268.300.000 Wh on board. To fit that into 205.000 kg requires a battery density og 1.300 Wh/kg.

      So where are we today. The best commercially available 21700 cells are 331 Wh/kg and Tesla says they expect to be able to compete with that shortly (Tesla 21700 cell is at 276 Wh/kg). This is still a factor 4 away from target and in the equation there is also the BMS and the thermal management system that both require power and weighs in.

      A level headed assumption is that we require a factor 6 more power density before we see zero emission aviation based entirely on batteries. There are a number of battery chemistries that promise that so given the intense innovation race I would not rule it out.

      However electric planes can go much higher than jet engine powered and thus limit air resistance and there is also the option to accept lower speed.

      Bottom line aviation will be electrified.

      • Alastair Leith

        Nope, there are already 2 seater trainer aircraft on the market and there’s one four seater two. They’re using what’s available on the market today, more density than what car makers are prepared to play with I’d expect but no where near 300 Wh/kg even.

        This was definitely a discussion of 100+ passenger aircraft I heard about. Maybe it isn’t 700 Wh/kg but that was the number that came from a back of the envelope calculation.

        • Jens Stubbe

          The Tesla NCA formula is not as safe as the NCM chemistry developed at Agonne National Lab and licensed to only BASF and GM. BASF sublicense and deliver the materials. They are more or less neck to neck but the Germans have an edge and also on pack level they are ahead so VW with AUDI and Porsche now are able to handle 350 kW charging. Porsche cannot sell battery cars that can’t charge fast as the rich crowd that is into conspicuous cars like Porches waits for no one.

          Anyway the innovation race is on and to the benefit of the passive bystanders.

      • Daniel

        I have heard that the other major advantage of FF powered jets is they get lighter as they use fuel, thus improving efficiency. Seeing as batteries retain mass as they are depleted this is a problem. I am also worried about how well a propeller will perform compared to jets.

        I hope that these issue will be overcome, I just don’t see it as a near term option for long hall aircraft.

        • Alastair Leith

          Long haul might not be near term but short haul under 350 miles for 100 passengers is being worked on right now. See the two links I posted in reply to Mark below. Longer distances and more passengers will come as surely as wind turbines got bigger and more efficient and batteries keep improving so quickly.

        • Jens Stubbe

          I am not generally of the opinion that we will see near term long distance hauling aviation. I think the sought after battery performance is perhaps two decades away. Earlier in the quest for better battery performance the performance grew exponentially with doublings every 10 years but as of lately the improvements go faster just as is the case for many other important technologies supporting the RE transition.

          Who guessed that onshore wind would suddenly pick up with huge cost improvements and who caught wind of the huge improvements in offshore wind?

          There seems to be a very constant widespread disbelief in the RE potential combined with a faith in shot term collapse in the very impressive innovation that translates into ever decreasing costs and performance improvements.

      • solarguy

        Well that’s concise. Are you in the aero industry or just a well educated buff?

        • Jens Stubbe

          The buff thing. We are currently looking into improving battery tech but only in a incremental way so will be the true contributor to battery driven aviation. I have a friend that is building a two seater and electrify everything that moves in a very hands on manor as he simply build or rebuild. DTU has provided the playground and they get grants and work together in flexible teams for free.

          • solarguy

            You certainly sound switched on about it. I day dream at times about designing and building a PV/ battery model as a tech demonstrator, using flexible cells. But I probably won’t get around to it.

            BTW what’s DTU?

          • Jens Stubbe

            Danish Technical University. This is the major technical University in Denmark and the number one university globally in regards to wind power closely followed by AAU.

            A delta wing design would certainly benefit a lot from light weight PV. I think a lot of drones have that approach.

          • solarguy

            Ok Denmark, where 30% of my genes come from. I take it then your Danish and well educated, fantastic.

            Great minds think a like a delta wing is exactly what I had in mind. In fact I have a RC model that I never got around to building and it’s aptly named the Delta. This a lifting body design, a flying wing, plenty of surface area. I thought of using amorphous cells underneath and mono cells on top of the body. My initial experiments have shown there is worthwhile power generated from amorphous cells with reflected light underneath, to add charge to the battery/

            What do you think?

          • Jens Stubbe

            I need to correct myself as i made a blunder and misread the specifications for the Dreamliner. The total amount of fuel is only 126.210 liters that weigh 101 tonnes at 20c.

            Sorry for the confusion I caused. This simply brings the possibility of battery aviation much closer than what I first assumed.

            The available weight for batteries goes down by 60 tonnes while the total power to be matched goes down to 1.212.000kWh. Assuming an average jet engine efficiency at 30% the Dreamliner carries 363.600kWh. while still assuming a factor 2 better aerodynamic efficient per seat we come to 181.800kWh battery capacity to match the Dreamliner speed and range. And to keep take off weight this has to be accomplished within a battery weight limit of 149 tonnes. So the needed battery capacity is in fact 1.220 Wh/kg at pack level and round about 1.600 Wh/kg at cell level and thus less than a factor 5 from current state of the art.

            A cassette holding system with a 3kg/L density would only take up 35 cubic meter and would greatly increase plane utilization and also allow fast adaptation of still better batteries and keep only batteries near pristine performance in the air, which eliminate the concern over battery degradation of cycle periods. Also this will allow charging with 100% RE power sources.

            Delta wing designs are the future as they deliver lift from the entire body and are easier to seat people inside so can carry more people for the same surface area and the same frontal area.


            The largest wind power rotor weighs 33 tons and has a diameter of 180 meter (Developed in Denmark by LM power for the Adwen 8MW now owned by Siemens Gamesa and LM power is now owned by GE) and endures far greater stress than any commercial airliner is designed for (hinged at the root while planes carries the body in center). A single blade (11 tons) is 50% longer than the Dreamliner wingspan at 60.1 meter.

            The exterior of the Dreamliner fuselage fits inside a box 68.3 x 5.77 x 5.97 meter so contains 2553 cubic meters.

            The wing area for the Dreamliner is 325 meters so assuming twice for a flying wing 1300 squaremeter (about the same total surface exterior area as the Dreamliner for fuselage, rudder, motor and wing) PV could certainly contribute a lot of power during daytime. First Solar CdTe is expected to reach 25% conversion efficiency – other more advanced thin film PV technologies (preferred for lower weight) are poised to exceed that and also the very low temperatures in aviation will likely deliver better efficiency.

            If you go for an average 1000W insolation per squaremeter and 25% conversion efficiency then the PV system will contribute 325kWh during daytime, which will further limit the required battery capacity over a 13.5 hours max fly time that computes to 4.400kWh or about 2.4% of the needed battery capacity.

            A more important effect by having a thin film solar cover is that it is an excellent deicing measure and will contribute more to range in that capacity.

            Many have discussed thrusters and Elon Musk has proven that he can return thrusters but just ground based thrusters could aid in getting the plane to take off speed.

            Others have speculated in charging with microwave beam in flight, which is probably on the fringe but have been a consistent train of thought for more than forty years.

            Aviation release about 2.1% of anthropogenic Carbon and contribute about 5.7% of anthropogenic GW effect and is projected to grow by a factor 3 onto 2050 if left unchecked.

            Bottom line battery aviation can and will happen inside a foreseeable future.

            Ps. The A380 with 853 seats was $25 billion in development or a staggering 75 times more expensive than the MHI Vestas 164 offshore turbine. And is now believed never to recoup the investments. Electric planes are way simpler to develop.

      • Ertimus J Waffle

        How do you come up with the conclusion that an Electric powered plane could fly higher than a carbon fueled powered plane, One big mistake you made is that the electric plane will be the same weight at take off as it is when landing and also as a carbon fueled plane burns it’s fuel load off it becomes lighter more efficient and can fly higher using less power. Have you factored those two factors into your calculations?????? I think your calculations are as useful as a fart in a football stadium and as calculations go is totally useless.

        • Peter F

          No need for the gratuitous insults.
          It is true that a liquid fuelled plane by definition gains range as the fuel is burnt off but it has to breath air so the flying height is limited by air density. The jet engine has a fairly narrow high efficiency range so the average fuel economy is always less than the ideal, The calculation is not perfect but is a very good first order approximation.
          It also suggests that if you could built metal air batteries close to the theoretical limit of 1,500 Wh/kg that would allow 10-12,000 km range vs the 787 14,500. This would handle the vast bulk of airline travel

        • solarguy

          What happens when you go higher in the atmosphere in relation to ICE engines, Waffle brains?

      • Peter F

        I know there is a long way to go but Lithium air batteries are hitting 1,300 Wh/kg in the lab.

        • Jens Stubbe

          Argonne National Lab has Lithium air going. Others are very keen on Silicon batteries with higher theoretic power densities.

          I think it is a foregone conclusion that aviation eventually will stop using FF.

          As a very minimum they will short term shift to RE based Synfuels/biofuels hybrids. Here in Denmark market parity will be reached within very few years. Better fuels does not solve the GHG problem entirely as the major problem is water vapor from the fuels and the second most important is soot whereas CO2 only comes third.

  • While the coal industry is successfully selling and building coal-fired power stations in developing countries, the Australian renewable energy industry is wasting its time and energy fiddling around the edges.

    Or to be even more blunt: this narrow focus is helping the coal industry by distracting attention from the front where the battle will be won or lost.

    If Australia’s renewable energy industry isn’t getting out and offering commercially viable alternatives to developing countries, it may as well be just another arm of the coal industry lobby.

    “The 1,200MW Nghi Son 2 power station in Tinh Gia district, Thanh Hoa province, is one of a number of large coal-fired power plants planned to meet Vietnam’s energy needs.”

    “Chinese firms to build Bangladesh clean coal plant”

    • Ertimus J Waffle

      Not all countries have a Death wish like Australia and most are run by people who want a better future for their population and CHEAP electricity to build a large industrial base with high value jobs.

      • Daniel

        All you can do is whine as renewables are built in mass around you, its not just in australia mind you… 70% of all new power capacity world wide built last year was renewable. Enjoy the transition 🙂

      • Peter F

        No everyone of those countries is generating a higher proportion of their electricity from renewables than us and investing more in renewables. In all of North America and Western Europe 3GW of new coal plants are under construction some 30GW has closed in the last 2 years and approximately 90 GW of renewables have been built. Last year China built 80 GW of renewables and 40 GW of coal and gas combined

    • Peter F

      Every one of those countries has cut back their planned coal build and for the last 3 years new targets have included less and less coal. Indonesia reduced its coal plans by 5GW recently Vietnam has done the same and Indian and Chinese plant completions are between 1/2 and 1/3rd what they were only 3 years ago and both countries are accelerating the closure of old plants

  • Jens Stubbe

    While Vaclav Smil might be overly pessimistic about the RE transition then is fair to note that the book was from last year when RE was considerably more expensive:

    Onshore wind power 30%
    Offshore wind 20%
    PV 17%

    This year onshore is projected to lower 10% but the record breaking 2017 was not anticipated. Offshore is projected to continue with 20% cost drop. Many have speculated about the PV cost drop this year. REC that supplies polysilicon have projected to be profitable this year as they were last year and expect to lower their prices by 13.6%. Other things than the core raw material impact the cost of PV but it seems highly likely that the normal cost decline rate will be reached.

    The reason why onshore wind has dropped a solid 50% in cost since 2014 is competition that has driven a strong innovation effort.

    The best way to show this is that the Vestas 3MW platform is now a 4.6MW turbine that weighs the same as in 2010 but has higher towers and longer blades and a more potent nacelle. Hidden in that is that every single element in that turbine have been fine polished to deliver more quality and longer lifetime.

    Onshore wind projects are now doing PPA’s in the US C1.2-1.8/kWh span including the PTC. When the PTC is no longer an option that will by the going of things still be the price point as the new generation of larger modern turbines are now going to be the standard in USA.

    Mark Diesendorf is skeptical about the Synfuels route that Smil apparantly favors. The DOE target was US $2.3/kg for Hydrogen by 2020 based upon US C3.7/kWh but the leader in the market place NEL stated last year before the record breaking RE cost drops in 2017 that they will sell hydrogen for $2/kg.

    Fully depreciated steam reform produced hydrogen based upon heavily subsidized Fracking gas in USA produces hydrogen for $1-1.5/kg.

    Everybody knows that deployment is the key for RE technologies so with such razor thin competitive edge only possible through massive subsidies then Fracking gas will loose that market over the next 5 years. In 2023 that market is believed to be $183billion.

    All the Hydrogen majors like Linde and Air Liquide have pledged GHG neutrality and Topsoe that is the principal in industrial catalyst and a major supplier of steam reform plants is also a major in SOEC electrolysis.

    Ps. Good luck with the world cup soccer game in a few hours – you might upset the Danish aspirations in soccer – but luckily never on the wind powered part of the RE transition.

  • Ertimus J Waffle


    Newcastle Herald

    Scott Bevan

    18 Jan 2017, 7 a.m.

    The resurgence in coal prices has flowed down the Hunter to help create a trade record for the Port of Newcastle.

    In 2016, the port handled more than 167.7 million tonnes, an increase of about 3.8 million tonnes from 2015. The trade value totalled $18.69 billion.

    Port of Newcastle’s Chief Executive Officer, Geoff Crowe, said the figures were “a good outcome”.

    • Mike Westerman

      Well this is current! Only a year and five months out of date…

      • Ertimus J Waffle

        I notice all the hair brained ways to generate electricity in the comments here have been talked about for nearly a decade or more and not one of them is commercially available.

        • Mike Westerman

          Baaaaaaaaaaaaaah…meanwhile the engineers are out building them. Must really piss you off to be so missing the mainstream…or maybe all the streams, just left cooking away in that waffle iron that no one is noticing

          • rob

            stroopwaffle is Dutch for a golden syrup filled waffle……sounds a bit like our friend!

        • Peter F

          So the fact that we are installing about 10 million solar panels and 600 wind turbines per year has escaped your notice, or the fact that more power will be generated from wind this year than hydro and probably as soon as 2020 wind will generate more power than gas and solar won’t be far behind hydro

    • solarguy

      Dick head!