PV storage: Horizon moves closer with solar smoothing

I read with great interest today that Horizon Power have introduced new standards recently for solar PV systems deployed on certain parts of their network that now require additional control mechanisms including “solar smoothing”.

Horizon Power, which services regional Western Australia, has introduced the changes to ensure that these “black holes” are avoided if large clouds pass by, for example. On large electricity networks this is a much less critical issue, but for Horizon Power, which operates a large number of diesel powered “micro networks” the issue can be quite pronounced.

Solar smoothing equipment essentially adds storage to solar PV systems avoiding sudden drops in solar power injection levels, which can make life very difficult for generators if solar PV penetration is high. The solar smoothing devices will provide back-up power to the grid while the generators ramp up and down – reducing the long term wear and tear of the equipment.

Horizon have set a range of “boundaries” around what is required, where and when which are summarised in the graph below and can be read about in more detail here.

Although this is a double edged sword – adding cost and complexity on the one hand and driving the deployment of advancements in solar with storage on the other – you have to acknowledge Horizon Power for not simply throwing their hands up in the air when it come to high PV penetration and integration issues.

The issue of solar PV storage has been a hot topic and many companies are heading towards market ready solutions and Horizon its seems, have just created a market for them, which is tremendously exciting.

WA based company Magellan Power has developed its own devices to address the opportunity and I called them today to get some background after reading an article on the issue here.

In short, they have a variety of customised solutions available and have been experimenting with LiPo batteries for several years in other applications, so are feeling confident that they have the right battery product. Like almost everyone else I have spoken to has told me, the key is in the Battery Management System (BMS) and Magellan have developed their own BMS in house.

Interestingly, although they offer a full turnkey package (batteries, inverter/charger, MPPT solar controller and housings) they are also able to integrate with existing inverters in some cases.

Ironically, it seems Horizon Power have moved the solar pv storage horizon just a little closer.

Nigel Morris is principal of Solar Business Services. This item was first published on his blog. Reproduced with permission. 

Comments

4 responses to “PV storage: Horizon moves closer with solar smoothing”

  1. Tim Avatar
    Tim

    Horizon also pays a generous feed-in tariff for areas where fuel costs are high. Don’t bother telling the WA government or the regulatory authorities, but solar PV means Horizon requires less of a subsidy to provide power!

  2. Power-to-Gas Avatar
    Power-to-Gas

    By the end of 2015 Germany will have a dozen Power_to_Gas plants in operation, ranging in size from 6kw to 20mw.

    World’s Largest Power-to-Gas Plant Opens in Stuttgart

    Oct 31, 2012

    Enlarge image
    The hydrogen is then converted to methane, which can be stored in the natural gas network, for use in this multi-energy-gas station for example.
    (© picture alliance / dpa)
    New power-storage technology is being tested out at the new power-to-gas plant that went into operation on Tuesday in the southern German state of Baden-Württemberg. The new plant “is the biggest of its kind in the world, with the ability to produce up to 300 cubic meters per day of methane,” the Baden-Württemberg Center for Solar Energy and Hydrogen Research (ZSW) said on Tuesday. The plant is located in the district of Vaihingen the Stuttgart metropolitan area.

    Franz Untersteller, the state’s environment minister, said that this was a “successful step in establishing new technology.” The ability to store energy is becoming even more important given that Germany is currently transitioning away from nuclear power – making renewable energy even more important. Water is split into its component parts of hydrogen and oxygen at the power-to-gas plant. The hydrogen is then converted to methane, which can be stored in the natural gas network.

    http://www.germany.info/Vertretung/usa/en/__pr/P__Wash/2012/10/31GasPower.html

  3. Mart Avatar
    Mart

    This has created an interesting situation where Horizon Power requires a PV-connected battery system while Western Power, the other WA grid owner, explicitly forbids it.

    Western Power’s rule, as stated on their website, is that a “PV system must have no energy storage connected (i.e. no batteries)”. Presumably this is meant to prevent customers from receiving a feed-in tariff for the export of battery-stored power.

    The perverse situation, however, is that most PV owners on Western Power’s network no longer receive a FIT (only a REBS fee which roughly equals the wholesale price of electricity), that more and more PV owners are installing battery systems anyhow, but that Western Power’s no-battery rule means that that these battery systems cannot be used for grid support.

    Even more perverse is the fact that Western Power itself is open to connecting battery systems and have them feed back into the grid, but that the WA Economic Regulation Authority has explicitly forbidden Western Power to include this option in their bi-directional reference service.

    In other words, Western Power customers are actually investing in distributed storage but an antiquated rule prevents both Western Power and its customers to use these investments in the most mutually beneficial way.

    I guess we now have to sit back and wait for the Barnett government to catch up…

  4. Lex - Solex Carnarvon Solar Farm Avatar
    Lex – Solex Carnarvon Solar Farm

    I suggest the impact of ‘cloud shear’ is not the primary focus of the utility. Boyle and Twidell and Weir do not address ‘cloud shear’ directly but it is interesting to note that Twidell and Weir look at energy variation in addressing wind energy harvest. It has to be recognised that wind is far more variable than solar irradiance however let us assume they are equally variable.

    Twiddell and Weir state ‘ power from the wind varies significantly and randomly. If the power from wind is no more than 20% of the total power at one time, then variations are usually acceptable within the ever changing conditions of the consumer loads.’ (2008:309.

    If we look no further it would imply that solar pv would be acceptable up to 20% of the grid system at any one time. Why then has the ‘hosting capacity’ been set lower? On what basis has the ‘hosting capacity’ been set?

    Further it has been suggested that in order to compensate for the variations in wind that wind generators be dispersed. If that is how the wind farmers address the problem why then does dispersed solar pv create a problem?

    I would like to see actual data from the power stations where solar pv is causing problems to energy variations. Where is the published evidenceto support the concept of ‘maximum hosting capacity’? I suggest this concept is driven by economic factors (reduction in electricity revenue) rather than electrical or mechanical ones – SHOW ME.

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