And now for the good news…. Those of you who read my columns may have noticed that while I’m generally optimistic I do tend to worry a lot about the big scary issues. In this piece I’m going to take a break from worrying and indulge in some unfettered technophilia.
Like most Gen X males, I’m into my gadgets. I follow new technologies pretty closely and when I can afford it I indulge in some cool toys like the latest smartphone or computer, etc. In the renewable energy field, there are a number of cool gadgets either already here or in development that should give us all some real hope for the future — a class of renewable energy technologies I call “exotics.”
The key trend for exotics is the improvement of information technology and its associated computing power. Moore’s Law — the rule that computing power doubles about every two years — is akin to magic when we ponder the fact that in the 60 years since Moore’s Law was formulated we have increased computing power by a factor of one trillion (2 to the 30th power)! This kind of computing power allows for an increasing control over our environment, or, at least, important parts of it. And this is just what the new exotics do.
eSolar is a Pasadena-based company that builds “mini solar power towers.” This type of solar power uses a central heat receiver to boil water and drive a turbine. The central heat receiver is heated by hundreds or thousands of “heliostats” — a fancy word for mirrors — arrayed around the central tower.
eSolar’s advance was to realize that computing power and control system technologies have advanced so far in the twenty or so years since the power tower was developed (and abandoned for some time) that much smaller mirrors could be used, at much less manufacturing cost. And that’s really it. eSolar’s small mirrors can be controlled very accurately by computer, resulting in far less costly and more efficient power towers. Attesting to the success of its technology, eSolar recently signed a deal with China to develop two gigawatts of power towers in that country. That will be enough power for about five million Chinese homes.
Nanosolar is another exciting new company — which just happens to also be based in California (San Jose). Nanosolar has improved upon the solar PV manufacturing business, a very different concept than eSolar’s. Nanosolar is apparently the first printing drum thin-film solar PV manufacturer to achieve scale. It recently began production from two facilities, one in California and the other in Germany. Its “big idea” is to literally print solar panels onto a metal substrate, using traditional printing equipment, which costs far less than the traditional solar manufacturing process. So while thin-film panels are still less efficient than traditional multi-crystalline panels, the cost of production is so much lower that they end up being a much better deal. (The only catch is that with less efficiency more space is required to achieve the same level of power production).
The wind industry is seeing similar improvements. A new “big idea” for wind turbines also relates to control systems. Turbines must face the wind directly to maximize power production. And as we all know from regular life, wind direction and speed can change rapidly and dramatically. Newer turbines also have pitch control, which means they can rotate the individual blades to maximize power production under different wind regimes. These adjustments take time, however, so if each turbine can somehow know in advance what the wind will be in a few seconds or a few minutes it can prepare itself to maximize production.
Catch the Wind Inc., based in Manassas, Virginia, has developed a “light detection and ranging” (LIDAR) device that is attached to each turbine. LIDAR is increasingly common in wind speed measurement when prospecting for good wind project sites. Mounted on a turbine, it can scan approaching winds from all directions and allow the turbine to adjust accordingly. Catch the Wind has completed testing of the device and claims it will result in about 12% increased production from each turbine. This is a huge increase in terms of the profitability of wind power projects and will allow turbines to be placed in areas where it would not have previously made economic sense to do so.
There are many even more exotic technologies, such as thermoacoustics, which use either heat or sonic energy to create electricity; solar pools, which use the sun to create electricity with temperature gradients or to desalinate water with reverse osmosis pressure differentials; sea water air conditioning, which use cold water from large bodies of water like the ocean or the Great Lakes to air condition entire city neighborhoods; and high altitude wind turbines, which float in air currents and are moored by long lines to the ground.
The key for any technology, once it has been shown to work and is capable of cost-effective production, is deployment. So for any of these exotics to really make a difference, we need to deploy them on a vast scale. There are some very encouraging trends for wind and solar, in particular, over the last decade. While wind and solar are “variable” because the wind doesn’t always blow and the sun doesn’t always shine, these technologies are capable of producing very large amounts of energy and there are many ways they can be “firmed up,” that is, their variability mitigated. So while there are many other promising technologies, such as geothermal and biomass, the rest of this article focuses on wind and solar because of their potential to be scaled up quickly.
The first decade of the 21st Century witnessed the coming of age of wind and solar power, with annual global growth rates of about 30% and 40%, respectively (see Figures 1 and 2, below). A 7% growth rate leads to a doubling every ten years. With a growth rate of 30%, doubling occurs every 2.3 years, and at 40% doubling occurs every 1.75 years. This is Moore’s Law in a new context: renewable energy growth.
Figure 1. Global wind capacity growth, 1996-2008 (source: REN21).
Figure 2. Global solar PV capacity growth, 1995-2008 (source: REN21).
So even though wind and solar PV are still quite a small percentage of today’s energy mix: about 1.5% in the U.S. and about half a percent globally, if we assume a sustained doubling rate of two years, wind and solar multiply 32 times in just ten years (two to the fifth power is 32). 1.5% times 32 is 48%. This means that if we can sustain the growth rates for wind and solar (ignoring for now other renewable energy like geothermal, biomass, ocean power and small hydro, which are very important complements to wind and solar), we can achieve a U.S. capacity of about 50% wind and solar energy in just ten years and a global capacity of about 16%! This should warm everyone’s heart. It certainly gives me some hope.
We” simply” need to sustain the growth rates of the last ten years, here in the U.S. and around the globe. This is no simple task, of course, and time will tell whether we do in fact sustain this growth. The official Energy Information Administration projections (the 2010 Annual Energy Outlook was just released) don’t support quite this level of future growth, but their projections are encouraging. The following figure shows EIA expects non-hydro renewable to meet fully 41% of all new U.S. electricity demand by 2035, with biomass (a baseload source of power) and wind power leading the way:
But EIA’s track record for accurate projections is abysmal, so let’s not put too many eggs in that basket.
Wind and solar, and other renewable energy technologies like geothermal and biomass, have established themselves as viable technologies and industries, capable of rapid and large-scale deployment. The challenges will be numerous: finding a steady and growing pipeline of new project sites that don’t arouse vehement opposition, continuing to lower production costs, and probably sustaining government financial and policy support over the next decade.
The growth of control systems technologies and “exotics” will help sustain this phenomenal rate of growth. Let’s not lose the momentum of the last decade.
Tam Hunt is managing member of Community Renewable Solutions LLC, a renewable consulting and project development company focused on community-scale wind and solar. He is also a lecturer at UC Santa Barbara’s Bren School of Environmental Science & Management.