And now Google Energy, too

Just after reflecting on my growing dependency on google for organizing my intellectual life, the company announced a new initiative to develop electricity from renewable energy sources that will be cheaper than electricity produced from coal (hence the name RE<Coal). The initative focuses good parts of its strategic investments and grants one one key technology, namely solar thermal power, to replace especially coal in traditional power plants that produce electricity from a steam-driven generator. Instead of producing the steam through the firing of fossil fuels, solar radiation is concentrated to heat piped fuels which then brings water to boil.

Using concentrated solar power (CSP) to produce electricity apparently seems to be increasingly viewed as the second renewable power source after wind to break into the mass energy market.

A quick characterisation reveals why:

• the heat produced from CSP can be used to operate traditional steam-cycle power plants. this can be done in solar-mode only or a hybrid modus, increasing so reliability and efficiency of the system (likewise can the efficiency of a combined cycle gas turbine plant again be increased through pre-heating of the water that is brought to boil by the gas jet engine exhaust; ISCCS)
• thermal storage is inexpensive and allows for night-time solar power generation. Co-firing with biomass and fossil fuels can additionally be used to to deliver electricity
• process heat from combined generation can be used also for seawater desalination
• it is a already a proven technology where high capex costs per MWh capacity as well as levelized energy costs are expected to profit significantely in the next 2 to 5 years

The investment costs range currently between 2'800 and 3'900 USD per MWh installed, whereas plant size as well as the size of the thermal storage key cost factors are. Levelized energy costs (LEC), which include operation and maintenance costs over the economic lifetime of the facility, are currently estimated at a range between 0.09 and 0.15 cents.

To reach a truely fundamental tipping point to beat coal, LEC of 0.04 to 0.06 cents will have to be achieved. The advent of utility-scale reliable renewable power though is already a promising outlook in itself!