What’s wrong with big solar in cities? Nothing, if it’s done right | RenewEconomy

What’s wrong with big solar in cities? Nothing, if it’s done right

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Suburban solar farm opposition suggests they don’t belong in residential areas. But what are the planning issues? And are there possible negative impacts?

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The Conversation

Many of us are familiar with developments of big solar farms in rural and regional areas. These are often welcomed as a positive sign of our transition towards a low-carbon economy. But do large-scale solar installations have a place in our cities?

The City of Fremantle in Western Australia is considering a proposal to use a former landfill site for a large-scale solar farm. The reportedly 4.9 megawatt solar power station on an eight-hectare site would be, it’s said, Australia’s largest urban solar farm.

The initiative is part of Fremantle’s ambition to be powered by 100% clean energy within a decade.

The proposal is facing some community opposition, however. Residents are reportedly alarmed by the potential public health consequences of building on a rubbish dump, which risks releasing toxic contaminants such as asbestos into the environment. Other concerns include glare from the solar panels, or excessive noise.

Similar complaints about solar panels in cities are being seen all over the world, with opponents generally of the view “they do not belong in residential areas”.

So what are the planning issues associated with large-scale solar installations in cities? And should we be concerned about possible negative impacts?

What is large-scale solar?

According to the Australian Clean Energy Regulator, large-scale solar refers to “a device with a kilowatt (kW) rating of more than 100 kilowatts”. A kilowatt is a measure of power – the rate of energy delivery at a given moment – whereas a kilowatt-hour (kWh) is a measure of the total energy produced (so a 100kW device operating for one hour would produce 100kWh of electricity).

Device here refers to not only the photovoltaic (PV) panels – the actual panels used in solar energy – but also to the infrastructure “behind the electricity meter”. So interconnected panels may still constitute a single device.

Solar panels adorn many buildings in Sydney, such as this one in Bringelly Village

By this definition, there may already be large-scale solar installations in Australian cities. In Sydney for example, the recently opened system on top of the Alexandra Canal Transport Depot is by all accounts a large-scale solar system. It combines around 1,600 solar panels with enough battery storage for 500kWh of electricity.

But this is not Sydney’s largest solar installation. That honour is presently held by the Sydney Markets in Flemington, among Australia’s largest rooftop solar installations, which generates around 3 megawatts (that’s 3,000kW).

To date, there have been no publicly disclosed complaints received about these facilities.

Large-scale solar (sometimes called “big solar”) can also refer to solar arrays that use mirrors to concentrate sunlight onto solar PV panels.

This is different to concentrated thermal solar, which uses mirrors to focus sunlight onto the top of a tower to heat salt, oil or other materials that can then be used to generate steam to power turbines for electricity generation.

What’s the problem with solar in cities?

Internationally, there is increasing recognition cities could be ideal locations for large-scale solar installations due to the amounts of unused land.

This includes land alongside freeways and main roads, flood-prone land, and rooftops on factories, warehouses and residences. And locating big solar in cities can also reduce the energy losses that occur with transmitting electricity over long distances.

Australia’s combined rooftop solar installations already supply the equivalent of enough power for all the homes in Sydney. And even former landfill sites – which have few uses other than parkland and are often too contaminated to sustain other land uses such as residential development – can be a good use of space for solar farms.

But such sites would need to be carefully managed so contaminants are not released during construction.

UNSW has set up a plan to have 100% of its energy supplied by photovoltaic solar energy

Large-scale solar installations can present some challenges for urban planning. For instance, mirrors can cause problems with glare, or even damage if they were misaligned (problems thus far have been in solar thermal plants).

Maintenance vehicles may increase traffic in neighbourhoods. Installing solar panels could cause temporary problems with noise and lighting. And views could potentially be disrupted if adjoining residents overlook a large-scale solar installation.

But not all of these impacts would be long-term, and they can all potentially be managed through planning approval, permitting processes and development conditions. Installing screens or trees can improve views, for instance.

Glare is a potential problem but again can be managed via screening (at the site or on overlooking buildings) or protective films on the panels.

The issue with the proposed solar farm in Fremantle is the fact it’s planned atop a former landfill site, known to contain harmful substances including asbestos, hydrocarbons and heavy metals.

Unless carefully managed, construction of the solar farm could disturb these materials and potentially expose nearby residents to health impacts.

Most state environmental protection agencies recognise risks if the use of potentially contaminated land is to be changed, and have developed stringent guidelines for landfill management.

The Algarve Lagos solar farm in Portugal shows how empty land in cities can be used to host energy efficiency platforms

The City of Fremantle has approved the proposed development, subject to the preparation of a site management plan among other conditions. Depending on site management, and the characteristics of surrounding neighbourhoods, poorly managed big solar on landfill sites could become an environmental justice issue.

From this perspective, residents’ concerns are understandable, and the City of Fremantle will need to ensure it carefully monitors construction.

Lessons for planning

It is reasonable to expect that cities will increasingly host large-scale solar installations. With careful site selection and management, the multiple benefits of clean energy can accrue to urban residents.

Otherwise leftover or marginal land can derive an economic return.

Of course care will need to be taken to minimise potential habitat loss or off site impacts such as visual intrusion, noise, and glare.

But solar farms also have the potential to provide new habitats both via physical infrastructure (sites for nesting) and as part of site rehabilitation and management.

Source: The Conversation. Reproduced with permission.

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  1. GlennM 2 years ago

    Yeah… I have solar panels on my house the noise is indescribable…

  2. Steve Applin 2 years ago

    The 30MW Byford Solar farm (WA) was/is supposed to be the first utility scale solar farm to be built within a metropolitan area in Australia. I was in the general area for work last week and drove past the site and there is no sign of any construction activity despite the farm having had a PPA in place and having appointed an EPCM contractor some time ago.

  3. Pedro 2 years ago

    I attended the community consultation at the Fremantle hall for the old tip site solar farm. I was surprised at the opposition which seemed to have be whipped up by a council by election candidate claiming all sorts of dire health risks. I think that most of the site is capped with clean fill of up to 10 meters. If I remember correctly, about 10-15% of the site, waste is at or near the surface.

    One proposal was for a very low profile no dig ballasted ground mount array using precast concreted blocks (similar to railway sleepers) with the panels in an east west orientation. The top of the panels would be about 1 meter off the ground. I thought it was a very good solution as the panels would shield the site very well from the prevailing SW winds reducing the amount of “toxic waste” that had previously being blown off site from the previous decades.

  4. MrMauricio 2 years ago

    There are vast areas of roof available on warehouses,factories,business and industry suitable for large scale solar-it aint that hard!!!

    • Andy Saunders 2 years ago

      Yes, if you look out of the window of a typical domestic flight it is striking how few commercial rooftops have solar panels as you fly over them. And their loads are often concentrated in daylight hours, making them ideal for rooftop PV.

      • Ren Stimpy 2 years ago

        It’s only a matter of price threshold…. Cleared for approach.

        • Andy Saunders 2 years ago

          Well it’s also a matter of retail discounts. If the energy rate drops enough it can be hard to make the financial case for solar PV

          • Ren Stimpy 2 years ago

            Retail schmishcounts.

            If it’s cheaper via cheap purchase/install costs for your own premises’ energy gen via solar and battery to offset your grid connect costs (and it will become significantly cheaper each year, for each of the next fifteen years at least for this tech) then who gives a flying figgus about retail yahyah?

          • Andy Saunders 2 years ago

            I understand what you say, but I think very few commercial businesses would find it possible to grid-disconnect.

          • Ren Stimpy 2 years ago

            Nobody is talking about grid-disconnect, just about cheap peak-hour disconnect which a relatively and increasingly cheap solar and battery system can do.

          • Ian 2 years ago

            The flimsy roof argument does not apply to most business premises, and the business case for solar up to the 100kWh mark at least, is very obvious. In the future we might have to ask our corner grocer, or tyre guy or chemist. “Where are your solar panels? I can’t buy your stuff. You don’t have solar.”

          • Steve Applin 2 years ago

            Ren I can’t say for the NEM, on the SWIS it’s not generally cost effective for larger businesses to install PV as the cost of electricity within an unbundled bill is considerably below the LCOE for rooftop PV.

          • Ren Stimpy 2 years ago

            The LCOE doesn’t include exports/FiTs. It’s common for solar owners to have a zero power bill, which even accounting for retail discounts is still a gain, just a slightly longer payback period than a residential customer.

          • Steve Applin 2 years ago

            The LCOE is the cost of producing the power from the panels, the FiT doesn’t come into it.

            On the SWIS, a typical large customer on an unbundled tariff is paying ~6 cents a kWh for their electricity, and the highest FiT I’ve seen someone paid is ~4 cents a kWh. However you want to twist that, economically, rooftop PV doesn’t stack up.

          • Ren Stimpy 2 years ago

            Yes the LCOE doesn’t account for the FiT.

            Over here on the NEM the minimum FiT will be 7.5 cents and will increase in stepped increments from 3:30pm

    • MacNordic 2 years ago

      While certainly true in some cases, there are some buildings where there unfortunately are hurdles for added PV: loading.
      Roof loads – especially in warehouses – are often designed to the bare necessary (legal) minimum – add as much as a satelite dish and you are above the certified load.

      While the individual panel is not that heavy, the required substructure and ballast does ad quite a bit of load. Around 35 to 70kg/ m² have been the standard weight in the past (data for Europe).

      New systems with loads of around 9kg/m² including modules have entered the market latterly. But the ballast requirements need to be custom tailored to the wind (&snow) loads at the relevant location, so might be higher in some legislative regions due to typhoons, storms, gales, heavy rain etc.

      The gist: some roofs might look tempting for solar, but the constructive roof load is to small, stopping the idea at the very start.

      • Phil 2 years ago

        Climate change may actually have assisted me there.

        My snow loading for the roof on a domestic dwelling is based on wind blown snow and ice from one direction as we are top of a mountain not far from Coffs Harbour

        But it has to be applied to the whole roof equally and i ended up with a snow loading equal to somewhere like Boston!

        And the snow events are virtually zero now with warming.

        So i’ve got a nice strong attic for storage instead to use that structural strength

        My solar panels are on top of a “reefer” shipping container so no issues there with loadings !

        • MacNordic 2 years ago

          ^^Definitely not going to exceed the 215t of possible load on a container with solar PV and snow;-)

    • Phil 2 years ago

      Actually there may not be as much as you think on warehouses
      Factories and shopping centers etc are usually OK

      Many of those warehouse roofs are so borderline weight bearing designed they collapse quite regularly in hailstorms and even Abnormal heavy rain events
      (now normal with climate change warming?)

      A solar panel weighs approx 20kg. So putting say 1000 of those up to get 250 KW adds 20 tonnes to the roof excluding mounts and cabling

  5. howardpatr 2 years ago

    Far better to develop the site as a urban solar farm than have left in its present state or have some develop want to rip the site up for housing. Very few homes will be impacted.

  6. jm 2 years ago

    Wouldn’t it be nice if we were offered the choice of solar or wind farms in the Inner City instead of Highways…. but we just having highways thrust over, or under, or through our houses.

  7. Francesco Nicoletti 2 years ago

    Every solar panel that goes into a brown field site is one that does not need to go into agricultural land or habitat. Probably more then one because of lower transmission losses.

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