Everyone knows we need green energy to fight global warming. But there’s another big reason to tap renewable power sources –- not enough water.

Large swaths of the Southwest and Southeast are in the throes of debilitating droughts. North Texas and Oklahoma’s recent dry spell dragged on from 2003 to the spring of 2007 (more on U.S. droughts). Droughts have even wiped out entire civilizations like the Anasazi (see Jared Diamond’s Collapse and Eugene Linden‘s Winds of Change).

But today’s water problems are far more profound than those of the Anasazi. The huge quantities we use — unprecedented in human history — make us more vulnerable to drought. Our water woes stem from an ever-increasing demand for water to slake the thirsts of a growing population on the one hand and to irrigate crops to feed that same population on the other.

Few people appreciate that yet another sector is clamoring for more water — the power industry. Fortunately we have the technology to wean this one from our dwindling supplies. (more…)

Every year the Renewable Energy Network for the 21st Century (REN21) and the Worldwatch Institute put together a profile and report card of the world’s renewable energy sector.

The REN21 Renewables 2007 Global Status Report found that last year, wind power capacity increased about 28 percent and solar power capacity went up 52 percent. Renewable energy employs 2.4 million people and 65 countries now have national standards for accelerating the use of renewables. Investors and businesses of all sizes have followed suit. And while that’s impressive, Mohamed El-Ashr, Chair of Ren21, had this interesting comment:

“So much has happened in the renewable energy sector during the past five years that the perceptions of some politicians and energy-sector analysts lag far behind the reality of where the renewables industry is today … This leadership has never been more important, as renewable energy has now reached the top of the international policy agenda under the United Nations and the G8.”

(more…)

Scientific American has a thought-provoking proposal in its January 2008 issue. The magazine proposes a massive, far-reaching plan to get solar power generating 69 percent of America’s electricity 35 percent of our total energy by 2050, thus replacing all of our foreign oil needs and slashing global warming emissions. Below are some of the highlights of that “solar grand plan.”

Technology

The American Southwest would be the home of massive amounts of solar power needed for this clean energy conversion. Specifically, two types of solar power would be employed: Photovoltaic (PV) cells and concentrated solar power.

According to the solar grand plan, 30,000 square miles of PV cells would provide 3,000 gigawatts (GW) of energy. The “30,000 square miles” part made me flinch, but already existing solar installations indicate that the land needed for each gigawatt-hour of solar energy in the Southwest is less that the amount of land needed to run a coal plant and mine the fossil fuel for it.

Concentrated solar power would supply about one-fifth of the solar energy in the plan. Concentrated solar power uses long metallic mirrors that focus the sun’s rays onto a pipe filled with fluid. The fluid is heated and runs through a heat exchanger that produces steam that turns a turbine. Nine plants like this already exist in the in U.S. (more…)

A report commissioned by the United Nations Environment Programme (UNEP) says that renewable energy is making a difference in the fight against global warming and that we need more of it. In fact, renewable energy is the best way to cut carbon dioxide (CO2) emissions.

At least 56 nations have policies that promote renewable energy and 44 countries, states, and provinces have requirements that a certain portion of their energy must come from renewable sources.

All told, the Renewables 2007: Global Status Report found that renewable energy continued its double-digit growth in 2007 and that more than 5 gigatons (5 billion tons) of CO2 were avoided. By the end of this year, investment in wind power, solar power, and other technologies should surpass $100 billion.

Wind power receives the largest share of that investment, beating out large hydropower.

So how to do we keep this momentum going? While renewable energy may have moved from an “alternative” source into mainstream use, Mohamed El Ashry, head of the global policy network REN21 that produced the report with the WorldWatch Institute, said that policymakers can do more:

“[Renewable energy] growth is being driven by policies to promote renewable energy, which have mushroomed over the past few years. What’s needed now are binding targets in an international agreement to establish policies that can rapidly accelerate the large-scale deployment of renewable energy to replace fossil fuels.”

Unlike the promises of future technologies like “cleaner” coal or mainstream carbon sequestration, renewable energy is the best option to mitigate global warming because it is here, now, and making an impact. The UNEP reports that the costs of renewable energy will continue to decline and that the clean energy sector is an avenue to economic development, energy security, local environmental benefits, and a global warming solution.

News Blaze
Reuters, via Thoughts on Global Warming Blog
United Nations Environment Programme

Since the energy crisis of the late 1970s, the federal government has employed various policy mechanisms to support renewable energy development. Driving through the neighborhoods that were developed in the late 70s and early 80s, it’s not hard to notice all of the old rooftop solar water heating arrays that were installed because people were taking advantage of a tax credit made available by the Carter administration. But the tax credit expired after Reagan took office, which is why I don’t see rooftop solar hot water nearly as much anymore (at least not recently installed).

The same thing will happen if the renewable energy tax credits expire (more…)

Wind turbines and solar photovoltaic have become the iconic symbols of clean energy and environmental consciousness. But what about the other less ’sexy’ forms of clean energy? Well, of course using less energy is the cleanest form to use, and it is usually the most cost-effective. But for people who want to increase the uptake of energy from clean sources, it may be more difficult. Unfortunately, not everyone has a strong enough wind or solar resource to make those investments cost-effective. Many folks living in urban settings would find it virtually impossible to implement either of those technologies. However, geothermal can provide or assist with heating and cooling needs for urban and rural alike. Geothermal exchange can be scaled for a single family home on up to entire city blocks, or more.

[kml_flashembed movie="http://www.youtube.com/v/lD82e5RYfW8" width="425" height="350" wmode="transparent" /]

Especially in the North American west, the geothermal resource is quite accessible. Now there are essentially two kinds of (residential) geothermal and I will not go too far into the details other than to say that one kind only needs to dig down 6-12 feet to tap the earth’s stored temperature. The other kind may take hundreds of feet of drilling but taps into a much hotter source. (There are also utility-scale geothermal facilities that are being developed in places where the source cannot be ignored, because hot waters bubble all the way up to the surface. Iceland, for example, gets 26% of its energy from geothermal and they get their remaining energy from hydro).