Renewable Energy

Jun 182013


Marine renewable energy sources such as wave and tidal power are poised to become an important part of the U.S. future clean energy mix. Recent Electric Power Research Institute (EPRI) and Georgia Institute of Technology studies have measured the annual technically recoverable energy from U.S. wave and tidal resources at 1,170 terawatt-hours (TWh) and 66 TWh respectively–a significant proportion of the 4,000 TWh of U.S. electricity demand. In practice, the realities of project development likely will result in a much smaller realized resource, but if 10 percent extraction can be reached, this would be equivalent to the output of 37 large fossil fuel plants.

The boom in natural gas production has undeniable benefits for the United States. But two policy analysts argue that embracing a monolithic energy future dominated by gas will mean the loss of a golden opportunity: Leveraging cheap, abundant gas to create a sustainable future based on renewable power.

by kevin doran and adam reed

13 Aug 2012   yale 360

Aug 152012

The folks at Energy Informative have a nice set of DOE renewable energy videos at this website:

This is a useful, objective, and  authoritative presentation of the costs of energy from various sources.

Jun 142012

“… we have estimated the total EGS resource base to be more than 13 million exajoules (EJ). Using reasonable assumptions regarding how heat would be mined from stimulated EGS reservoirs, we also estimated the extractable portion to exceed 200,000 EJ or about 2,000 times the annual consumption of primary energy in the United States in 2005. With technology improvements, the economically extractable amount of useful energy could increase by a factor of 10 or more, thus making EGS sustainable for centuries.”      Read the entire MIT report:  The Future of Geothermal Energy (November 2006) here:

Exajoules are actually a pretty useful energy measure.  1 Exajoule is about 278 TWh.  Earth always needs a steady flow of something between 12 and 18 TW of energy from all sources.  Estimates vary from source to source but are always within this range.  1 TW = 1 (24) (365) = 8760 TWh

So the planet needs something like 15 x 8760 = 130,000 TWh of energy from all sources annually or about 470 Exajoules.  Nice small numbers because EJ is a very big unit.

Does this  agree with 200,000 EJ being 2000 times the annual consumption of primary energy in the US in 2005?

Primary energy consumption was about 27,000 TWh for the US in 2005 which is about 97 EJ.

So, yes, 200,000 EJ is about 2000 times the annual consumption of primary energy in the US in 2005.

The US can access 200,000 EJ of geothermal energy using Enhanced Geothermal Systems and we need 100 EJ of energy from all sources per year.  EGS will last a while!


From Solar Daily, Abu Dhabi, June 6, 2012:

According to the study by the Abu Dhabi-based International Renewable Energy Agency, the costs associated with extracting power from solar panels has fallen as much as 60 percent in just the past few years.

The price of generating power from other renewables, including wind, hydro power, concentrating solar power and biomass, was also falling.

“One of the (myths) out there perpetuated by industry lobby groups is that renewable energy is too expensive,” said Adnan Amin, IRENA’s director general.

Read the complete article at

June 8, 2012.  As reported by Renewable Energy World, “A new report from the Renewable Energy Association (REA) says the UK could meet a fifth of its power needs with geothermal energy, according to the Guardian. Geothermal could supply 9.5 GW of electricity, about 20 percent of current demand. It could also supply 100 percent of the UK’s space heating needs with about 100 GW of heat.”  Read the complete article at

At the website below you can download, “Delivering On Renewable Energy Around the World:  How Do Key Countries Stack Up?” by the Natural Resources Defense Council.  There is a colorful interactive map color-coding the G-20 countries according to the percentage of wind, solar, geothermal, wave, and tidal energies.  Hydropower is not included, probably because it would obscure the message about the other renewables.

Jun 122012

27 Jan 2012

Nur Energie’s CEO, Kevin Sara, says: “TuNur is going to be the blueprint for things to come. It is a pioneering project that other governments, companies and individuals can point to and say, ‘Solar energy export from North Africa to Europe is possible, it’s worthwhile and the DESERTEC vision is attainable’. We are used to transporting exhaustible fuels like oil and gas thousands of kilometres and then burning them close to our cities with all the associated pollution problems and other risks to humans and our environment.

“Now, with the TuNur project, we are turning away from these polluting fuels to transmit clean and inexhaustible energy from the heart of the desert to European homes whilst, at the same time, bringing jobs, economic development, and export revenue to Tunisia.”

Read the whole article at

Remember that 2 GW of nuclear power is about 2 reactors, but 2 GW solar, while a lot for solar, is probably a bit less than  25% of 2 GW on average or more like 1/2 a reactor.  The sun shines at most 6 hours peak sun/day even in the Sahara.