Kevin's Comments

Capturing landfill gas generated by waste that has already been buried and using it to produce electricity or useful heat is a good thing. Otherwise the gas would just be flared. However, waste generated in the future should be either recycled, composted or burned (which depends on the type of waste and the local needs and infrastructure). The reason for this is that burying waste and collecting the gas that happens to form is a very inefficient way of using the waste. Much of the waste does not decompose and produce gas. Instead, what can be recycled economically and without using more resources than it is worth should be recycled. Whatever is left over should be burned or processed in an anaerobic digester, as long as anything hazardous has been removed. Organic waste can also be used to produce compost, if desired. The only thing that should be going to landfills is waste that cannot be reused, recycled or used to produce energy.

It would be preferable to burn the waste directly rather than just collecting and burning the gas that it produces. First, a lot more energy would be produced because most of the waste does not decompose in a landfill. About half of landfill gas power plants in California are under 5 MW, with many being less than 3 MW. Only 15% are over 10 MW, and only two plants are over 13 MW. A municipal sold waste (MSW) power plant is likely to have a capacity several times larger than a landfill gas power plant that receives the same amount of waste. I would estimate that a plant replacing an average landfill would be 10 to 25 MW, with larger plants being up to 50 or even 100 MW (the landfill would not be fully replaced as about 10% of the waste volume would still need to be disposed of as ash). A MSW plant also has the advantages of metal recovery, greatly reduced volume and destruction of some types of pollutants. It should be noted that recycleable materials and hazardous wastes are not burned, at least in U.S. plants.

Upgrades and increasing efficiency at existing hydroelectric plants and putting in hydroelectric systems when the water is already being diverted anyway, such as for irrigation or drinking water, is how we should get virtually all of our new hydropower output. The best locations already have plants and it would be criminal to add hydroelectric plants when the output would be small, unless the water is not already being diverted for human use. In addition, we should remove hydroelectric plants and dams that have a low output for the amount of damage they cause to the environment. There are many plants in Southern California like this, such as the plants on the Santa Ana River and its tributaries Mill Creek, Bear Creek and Lytle Creek (7 plants total). Since the amount of rainfall in Southern California is not great, the streams are completely dry in some places because all of the water has been diverted for power generation.

It would be wonderful if cellulosic ethanol could be made commercially viable. Producing ethanol from corn is only a little better than break even and is a waste of good farmland. Cellulosic ethanol could be produced with waste products, like logging residues and the inedible parts of crops, which would mean that no new farmland would be needed. Also, the efficiency would be improved dramatically because no additional energy is needed to grow the material since it is a waste product and is therefore produced whether it is used for ethanol production or not. Even if crops are grown to produce the cellulosic ethanol it would still be superior to using corn because cellulose is much more abundant in plant matter than starch is in corn (the starch in corn is what is currently used to produce ethanol). Also, switchgrass, which can grow in marginal soils and does not need much water, could be used to produce ethanol.

The wording of the article title is not perfect. After reading it, I thought that SunPower had previously acquired PowerLight and was now closing it. I am relieved that is not the case. PowerLight is frequently mentioned when a large photovoltaic array is installed in California, whether they installed it, provided components or both.

I doubt they would be doing the project if it was a risk to the aquifer, given what a valuable resource it is. They could also use tanks for CAES. I do not know how they compare economically. While geologic formations may have large volumes, you can get tanks up to much higher pressures.

For now, biomass energy only makes sense when it is using waste materials, like sawdust, farm animal manure, pruning wood, sewer gas and non-edible plant parts. That takes the energy and resources used to produce the biomass out of the equation, as the waste would be produced whether it is used for energy or not. This greatly improves the cost and overall efficiency of the process. Also, additional farmland is not required when waste is used. Besides saving the water and resources (like fertilizer, pesticides, farm equipment and its fuel) that would have been used to produce non-waste biomass, it also prevents additional wildlife habitat from being made into farmland. This posted is continued below.

The U.S. could produce a significant amount of its electricity using waste biomass, especially if waste-to-energy plants that burn or gasify trash are used. Most hazardous materials would be diverted through hazardous waste programs and the rest would be removed from the waste. Also, everything that could be recycled would be, as long as it does not take more energy and money to recycle the type of waste than is saved. With the latest pollution controls, emissions would be only slightly higher than natural gas plants and much lower than coal and oil. In addition, the plants reduce the waste's volume by several times, saving landfill space, and the ash is less toxic than the garbage if done properly. Finally, waste is already being widely burned indirectly by landfill gas power plants and flares. Burning or gasifying the waste in a plant would be far more efficient, produce far more electricity, and emissions per kilowatt-hour produced would be equivalent, if not better.

I think this would be useful for hybrid vehicles. The solar cells could be used on the passenger and back windows, and possibly the front windows, depending on how much light is blocked. If they were combined with more efficient solar cells on the roof and possibly the hood and/or trunk, the car could run on electric power a lot more of the time. While the car is parked, the batteries would be charged and while it is moving, their would be enough power to significantly increase the car's range and gas mileage. The cars would need a more battery storage than they have currently to take advantage of all of the power produced while the car is parked, though. It would be great if they had enough storage capacity to go 25 or 30 miles on battery power alone because most trips are shorter than that.

It was foolish of the Cape Wind developers to continue the project in the face of so much opposition. It generates a huge amount of negative publicity and makes people scared that wind turbines are going to be forced on their community. Now they have caused politicians to make legislation that threatens the entire U.S. wind industry. It's the politician's fault for passing the harmful legislation, of course, but what do you expect from politicians - they're the champions of NIMBY to please their electorate and they have business and personal concerns (like land in the Cape Wind case) that affect their motives. The Cape Wind developers should have pulled out long ago.

Wind developers should not give up at the first sign of opposition, but a high profile, vicious fight like the Cape Wind project damages the whole industry by generating negative publicity and inspiring legislation that negatively affects wind development.

Oil does not yet compete with wind energy because wind turbines produce electricity, while oil is used mostly for transportation, with the unusuable dregs used for electricity generation. It may change in the future, if wind energy is used to produce hydrogen for use in vehicles or for charging electric vehicles.

For renewable energy companies, being acquired by a larger company has advantages, like more economies of scale, a greater ability to weather a crisis and being able to operate at a loss when just starting out (not a problem for Vestas). However, since the business is not as dependent on the income produced through renewable energy, they may be more likely to sell the company or discontinue production altogether at the first downturn for the company or the industry. Also, if a company that is not committed to renewable energy has the chance to slightly increase profits by switching to a less environmentally friendly technology, they will take it

In response to Rich Barbarics, there is not enough photovoltaic modules available to do that. The military is had a hard time finding enough for a 18 MW plant. It will be years before production catches up to demand and some plants need to be built now. If solar thermal were not available, natural gas or coal will be the only alternative. Also, solar thermal is cheaper per kilowatt (plant construction) and per kilowatt hour (energy cost). Solar thermal has more economies of scale, as well. Cogeneration, perhaps the biggest advantage of distributed generation, is not used in photovoltaics or solar trough (although it could be used in solar trough). The only downside of concentrated generation, in this case, that I can think of is if the plant had to be located so far from the consumers of electricity that a significant amount of electricity is lost. However, that is not the case for these plants.

I think it might be better to go with a solar trough steam-electric plant or an array of solar dishes with stirling engines for large projects. Solar towers, the kind with heliostats not the chimney one, are an option, but I think that solar troughs are cheaper. There are also solar ponds, but I think you would need a lot of them to make 18 MW of peak power.

Photovoltaic panels seem better for small installations. They are more costly per kW, but you don't have to build a power plant like with the solar trough. They also don't have as much of an economy of scale, as the main cost is the modules. A small solar dish could be used at a home or small business installation, but photovoltaics are less obtrusive and can be placed on existing structures.

Unfortunately, he reduced spending for staff, so the NREL had to fire people.

I support renewable energy, but solar does not reduce the use of oil because not much electricity is made with oil, about 2 to 3% in the U.S., and it is mostly the leftovers from distillation that nobody else wants. The same is true of nuclear energy. We would need electric vehicles that plug into the electrical grid in order to use solar or nuclear energy to decrease oil consumption. Either that, or make solar or nuclear powered cars. Without electric cars, wind energy, geothermal energy, hydroelectricity, wave power and biomass (except biodiesel and ethanol) do not reduce oil consumption, either. However, if production were substantially increased, renewable energy would displace coal, nuclear and natural gas, which produce roughly 50%, 20% and 16% of U.S. electricity respectively.

Using biomass waste for fuel is the most efficient way to go. It is wasteful, in energy and water, to use edible crops for energy production.