According to the US Energy Information Administration, the installation of solar photovoltaics in the United States increased by more than 400% from 2010 to 2014. Looking towards 2015 and beyond, industry analysts continue to be bullish on solar’s continued growth in residential, commercial and utility scale projects stemming in large part from the drop in silicon prices, the corresponding drop in the prices of solar equipment, increased efficiencies with integrators/installers and equipment, new and creative financing structures that exist in the marketplace and a greater acceptance from consumers and businesses as to the value proposition that solar systems offer the end user. Succinctly stated, solar manufacturers, developers, integrators, finance companies and end-users have a great deal to celebrate.
Notwithstanding the foregoing, the industry as a whole is not without its critics. One of the most common and consistent complaints when compared to non-renewable energy producers is that solar cannot scale in any measurable level for grid usage because it is only an intermittent and variable source of energy that is unable to meet peak demands 24-hours per day. However, this barrier to market acceptance is not insurmountable and regulatory mandates, renewable portfolio standards and venture capitalists are combining forces to drive the industry toward a viable solution – energy storage.
Energy storage for solar and other renewable energy sources is not new, but it is only in the last few years that it has really started to emerge (or re-emerge as the case may be). The types of potential storage vary between residential, commercial and utility scale projects and the specific technologies used. A summary of characteristics often utilized by the market participants include pumped hydro, compressed air (underground and aboveground), flywheels, lead-acid batteries, lithium-ion batteries, flow batteries (Vanadium Redix and Zinc Bromide), Sodium Sulfur, power to gas, capacitors and Super Magnetic Energy Storage (SEMS). As for the market participants themselves, we are seeing multi-national institutions such as General Electric and AES Energy Storage, solar developers and manufacturers such as SolarCity and SunPower, renewable energy integrators such as Magnum Energy and MidNite Solar, start-ups such as LightSail Energy and Aquion Energy and even car companies such as Tesla Motors and Audi. The increase demand for storage has arisen partially as a means to enhance long term relationships with end-users and off-takers with fully integrated solar-storage combinations, while, at the same time, positioning the renewables industry to meet peak energy demands as and when needed.