THE NEW POLISH RES LAW NEEDS TO PROMOTE ENERGY STORAGE
Poland has a unique opportunity to avoid some of the problems now confronting Germany, as intermittent renewable energy sources take over the first slot in meeting demand for electricity. It has been widely reported that as intermittent energy sources play a larger role in the grid supply, more pressure is placed on “ramping up” power to meet demand peaks. Coal plants are notoriously poor at ramping up or simply backing up renewable energy sources, since they require a high utilization rate to remain economically viable. In this regard, Poland is more vulnerable to mismatched supply and demand than many other countries. This has been one of the main concerns of the Polish Government is debating the new law on renewable energy.
Yet the Government’s various versions of the law have never dealt in any fashion with energy storage. The term does not ever appear in the different versions of the law. Energy storage is viewed as vital to bridge the gaps in energy supply. The European Commission, DG Energy Working Paper onEnergy Storage, last year summarized the importance and role of energy storage:
Energy storage can supply more flexibility and balancing to the grid, providing a
back-up to intermittent renewable energy. Locally, it can improve the management of
distribution networks, reducing costs and improving efficiency. In this way, it can ease the market introduction of renewables, accelerate the decarbonisation of the electricity grid, improve the security and efficiency of electricity transmission and distribution (reduce unplanned loop flows, grid congestion, voltage and frequency variations), stabilise market prices for electricity, while also ensuring a higher security of energy supply.
They provide a graphic illustration of the benefits of energy storage:
As the July 2014 version of the new RES law is debated and amended, it needs to address energy storage, at least in a preliminary manner. Right now, if intermittent renewable energy producers store electricity either to smooth very short-term fluctuations or to address peak/off-peak concerns, the stored energy is not clearly covered by the support scheme. So a RES facility would have to store electricity when it could be sold at a premium and re-introduce to end-users at a lower price without RES support. This is a totally illogical and unwise situation.
Clearly, energy stored from RES sources covered by the support system should receive at least the same level of support when it is released for use. Any other approach makes energy storage, which is vital to the future system, impossible at inception. The European Commission makes the point: “It is important to ensure that electricity from RES keeps its RES label, even if it has been stored before the final consumption. Possible feed in tariffs should not be affected by intermediate storage.” DG Energy Working Paper. A more logical system would place a premium on off-peak electricity generated and stored to be discharge during peak hours. Besides helping RES producers, this would reduce the aggregate difference between peak and off-peak demand and increase the utilization rate of the traditional fossil-fuel energy plants.
A bigger market lesson can also be drawn upon from the emerging energy storage sector. The California Energy Storage Alliance, operating in the most advanced energy storage market in the world, reported earlier this year that a 40% differential between peak and off-peak electricity rates can make energy storage with today’s technologies economically viable. [Janice Lin, California Energy Storage Alliance, Energy Storage- Europe conference, March 24, 2014]. This is, of course, only true if the facility can receive the higher peak rate differential. Under a feed-in tariff as proposed in Poland for winners of the auctions, there is only one rate envisioned and no financial incentive for storage and discharge during peak hours. A means to finance investment in energy storage is essential and failing to utilize the natural market mechanism seems to be extremely short-sighted.
Multiple technologies are now available to provide for energy storage on different scales and with different temporal capacities. The appropriate system varies with the application, whether it is to even short-term fluctuations or to reduce peak/off-peak peaks and valleys. The Polish system is typical in that it is very inefficient due to the need to have capacity for peak hours and seasons, which is unused the rest of the time. See chart from URE data:
URE website, Load of the Polish Power System from Jan. 2011 to July 2014.
Technology exists to reduce this "wild ride" as well as to smooth shorter term variations. These systems include advanced lithium ion and other battery systems, fly wheels, compressed air, traditional pumped hydro, and other innovative solutions. The Edison Electric Power Research Institute reported a benefit to cost ratio over one for nearly every technological scenario. “Cost-Effectiveness of Energy Storage in California,” Application of the EPRI EnergyStorage Valuation Tool to Inform the California Public Utility CommissionProceeding R. 10-12-007 3002001162 (2014). The recognized need for energy storage occurs at each level of the energy network, as illustrated by DG Energy’s schematic:
The ability to differentiate between peak and off-peak prices can provide a key incentive to provide energy storage capacity in the integrated electrical system, especially at the pre-grid distribution level. See above graphic.
We are working now to formalize the Polish Energy Storage Association and to hopefully start a constructive dialogue immediately with the Polish Government on how to provide the preliminary support for this essential sector. It will be necessary to obtain cooperation from all of the interested energy storage technology providers, and other stakeholders to achieve the right solutions.
Introduction translated by www.photonlab.pl. Thanks!
 For biogas, the storage can be in the form of methane and it can be used to generate additional power during peak hours. This is an unusual characteristic for renewables, but requires that a higher price be charged to finance the additional storage and generation capacity. This can be done under the current Green Certificate system, which allows direct sales, but will be lost under the auction system that requiring one flat rate for grid sales.