Issuu on Google+

The imperative case for a renewable energy future Here’s a frightening thought. The world’s easily-exploited fossil fuels are no longer available – we’ve used them up. That means our current fossil fuel sources require an already-advanced technological society just to extract them. If we haven’t perfected renewable power generation by the time fossil fuels are no longer viable, the next industrial revolution on earth might be tens of millions of years away (when the next batch of easy-to-reach oil is cooked). The legacy of the fossil fuel era should be that they have given us a leg-up to become advanced enough to exploit the stupendous quantities of energy provided daily by the sun (in the form of wind, hydro, and direct solar power). Energy from the sun – at least on the earth’s surface – is diffuse and unsteady, so when we consider using solar power, storage should be front of mind. Ironically enough we have been using stored solar energy for years in the form of the combustible carbon in coal and oil, produced millions of years ago by photosynthesis. But solar energy can be stored in other ways: as pressure wherever rainwater is held behind a dam, as hot water in insulated tanks, as high temperature molten salts in large-scale solar thermal plants and as chemical energy in our most ubiquitous form of energy storage – batteries. Renewable energy storage is essential because we can’t wait for the sun to be shining before we turn on our appliances. But because the amount of solar energy available is so enormous, it is easily possible to design solar power storage solutions to store enough during the day to use whenever the sun isn’t shining. So how much solar energy falls on the earth? Well, in full sun, it’s about one BTU per square foot every 8 seconds (or one kilowatt per square meter). But there’s a more useful way to think about it. The Energy Information Administration calculates that total US electricity demand over a year is a sizable 15 quadrillion BTUs (or about 16 exa-Joules). The area of solar panels required to capture this much energy (taking into account inefficiencies and energy storage – batteries or other methods) is about 10,000 square kilometers, which is the size of Hawaii’s main island, or three times the size of Long Island, New York. Big, but not that big. We’ve built far bigger – for instance it’s about one third of the current area of roofs in the US (using US Department of Agriculture figures). Combining solar sources and renewable energy storage we have not just the opportunity, but the responsibility now to leave our fossil fuel past behind us and embrace the power of the sun.


__________________________________________________________________________________ Resource Box/Author Box: Ecoult delivers complete energy storage solutions and modules powered by the breakthrough UltraBattery technology – a hybrid lead-acid energy storage device containing both an Ultracapacitor and a battery in a common electrolyte. Ecoult’s storage solutions manage intermittencies, smooth power and shift energy in a safe, reliable and environmentally sound way – the energy storage of choice for grid ancillary services, wind and solar farms, remote Microgrid Energy Storage, dual purpose and diesel microgrid efficiency applications. For more details regarding our energy storage solutions visit our website or call us at our toll free number +61 (02) 9241 3001.


The imperative case for a renewable energy future