What Google is doing is the leading edge of something they refer to as "corporate solar." It's an expansion of the residential solar that places photovoltaic panels on the peaked roofs of houses with southern exposures. Those cells generate typically 2.5 to 5 KW of DC that is electronically inverted to utility grade alternating current and fed back to the grid through a two-way electric meter. When the sun shines brightly, the power meter runs slower and slower and then reverses to indicate that the home is a net generator of power. The value of the power that back feeds the grid is subtracted from the value of the power that the house draws from the grid at night and on cloudy days.
You can get a lighthearted tour of this serious technology from Ed Begley, Jr. on his new TV series "Living With Ed". Ed's been an environmental activist for decades, typical of the early adopters for solar energy. Up until recently, "green" power has been more of a rallying cry and personal commitment than a mainstream real estate investment. That's pretty much changed now. The cost of solar panels, the frames of photovoltaic cells that convert inbound photons to flowing electrons, has steadily dropped. Technology advances have made the solar conversion process more efficient and created new types of panels, some of which resemble common asphalt shingles. The cost of the inverter electronics that converts solar cell DC to power line AC has also come down. Combine these improvements with government subsidies of up to 50% and laws mandating that electrical utilities buy power from individual producers at the same rate they sell it, and you've got systems that pay for themselves before they become obsolete.
Now solar power is an investment, not an expense. This couldn't have come at a better time. The information society is a power hog, perhaps even worse than the industrial revolution. Network operations centers are getting to the point where they can suck electricity faster than a steel mill. It's actually a double hit. Electric power runs the CPUs, which heat up and need more electric power to run air conditioners to get rid of the heat. In the steel mill everybody sweats. In the server room, the equipment and personnel need to keep cool or they'll both go nuts. The Mountain View Googleplex pulls just under 5 Megawatts at peak loading.
So where do new Megawatts come from to power the expansion of technology industries? Traditionally, it's nuclear with glow in the dark for generations ramifications or coal with terraform the Earth to something like Venus ramifications.They both suck, but what else can you do? Burn natural gas? That pumps out CO2 just like coal. Burn Oil? Oh, please. That's CO2 and supply limitations combined. Hydro? We've pretty much dammed everything that still flows.
That leaves us with solar and wind as renewable and freebie energy sources. The energy is free. The equipment to capture it requires a strategic investment. Google is plastering solar cells over all their rooftops and building parking lot shelters with more solar cells on the roofs. All of that will give them 1.6 Megawatts or 30% of their power requirement.
As you expect, solar is a daytime energy source. It fizzles out when the sun sets. So at noon you may be offsetting a huge portion of your energy need, but at night you draw 100% off the grid. That's actually advantageous, because power demand is highest during the day when that beating sun makes air conditioners run longer and most people are in their offices with computers and lights on. True energy independence will require both solar and wind, plus advanced nuclear, biofuels and natural gas fired peaker plants. It will also require new building designs to get lighting as well as power from the sun.
That's for now. Google's shot across the bow of the old energy industry will hopefully get other companies interested in coating the flat and otherwise unencumbered roofs of their offices, factories and warehouses with photovoltaic panels. Residential construction can do likewise, creating a huge resource of distributed power that is more reliable and more secure that putting all the generators in one spot and running transmission lines across the countryside. A corporate stampede to "be just like Google" could change our strategic energy situation almost overnight. It happened with downsizing, it happened with quality, it happened with outsourcing... and it can happen with solar.
