Graph of the Day: Commercial solar storage tipped to boom  

ReNew Economy has a post on the growing solar PV energy storage industry - Graph of the Day: Commercial solar storage tipped to boom.

There has been no shortage of big talk about the huge, and as-yet untapped potential of the global solar energy storage market, mostly revolving around growth in the residential and utility-scale PV sectors. But this week, a new report by energy analysts IHS has predicted that commercial PV storage will become the largest player in the market, with projections suggesting it will grow by a factor of 700 by 2017.

Currently the smallest market segment at just 3.2MW, commercial storage is due to mushroom to almost 2.3GW by 2017 – from 5 per cent of the market to 40 per cent in five years – according to the IHS report ‘The Role of Energy Storage in the PV Industry’.

RNE also has a related post on energy storage for solar thermal energy - Return of the steam engine: cheap storage for solar.

Not long after Robert Mierisch finished up as director of thermal systems research at the solar thermal energy pioneer Ausra, he took himself to the Smithsonian in Washington, the world’s largest museum complex, to find out everything he could about the Skinner steam engine.

Mierisch was playing on a hunch. Or should that be a conviction. He had worked with solar thermal energy for years, and had been looking for a viable storage solution. He thought he could find the enabler in comparatively ancient technology.

Steam turbines, he reasoned, couldn’t do the job at the scale he had in mind, nor did they have the flexibility required to replace diesel power. But steam engines just might. This is what led him to the Smithsonian and the Skinner Unaflow steam engine, which were used in ships through the 1940s, the last commercial version of the steam engine that had begun at the start of the industrial revolution nearly 200 years earlier.

Now, a unique distributed generation technology with storage, the product of a 4-year collaboration between Mierisch and Steve Bisset, another Australian expat and Silicon Valley entrepreneur, is soon to see the light of day.

Terrajoule, the Redwood City, California-based company they co-founded, will soon bring a demonstration system up to full-power operation, generating 100 kW for 24 hours per day. This is a key milestone toward bringing the solar/steam/storage technology to market within the next 18 months.

Mierisch and Bisset say their technology is potentially revolutionary but deceptively simple. It combines inexpensive solar power with inexpensive storage and behaves like an electric motor plugged into the grid, or even like a diesel genset. In other words, it can operate 24 hours per day, but without the utility bill or the fuel cost.
 And they say it will be cheaper and far more efficient than alternatives such as solar PV combined with batteries.

RenewEconomy was invited in July to visit Terrajoule’s demonstration site near Oakdale, on an irrigated almond farm in the heart of the California Valley, about 150kms east of San Francisco (see photo).

There, Terrajoule has an array of parabolic trough receivers that collect solar energy to create steam to drive the engine. The breakthrough comes from the realization that the storage can be created by exploiting the difference between the high pressure and the low pressure cycles of the engine.