by John Farrell, via the Institute For Local Self-Reliance

A new study for the California Public Utilities Commission explores the “Technical Potential for Local Distributed Photovoltaics in California.”  Basically, it’s one of the more in-depth analyses of local solar power in the country, suggesting that California has the capacity to add 15 gigawatts (GW) of local solar (20 megawatts and smaller) to its grid by 2020.  The study pushes the boundaries of distributed generation by assuming that local solar can be installed sufficient to meet 100% of local demand, far beyond the conservative “15% rule” that utilities typically apply.

There are the usual caveats about the technical limitations of the current grid, but a few graphics from the report provide a glimpse into the implications of a distributed generation future.

This first chart shows supply curves for various types of distributed solar under their 15 GW scenario.  What I find interesting is that the biggest chunk of distributed solar is not on the ground or on commercial roofs, it’s residential rooftops.  Half of the state’s distributed solar potential is on residential rooftops.

This next chart illustrates the cost and benefits of residential solar PV for a PG&E substation in Fresno, CA.  What I find interesting is that 6-7 cents of the levelized cost of solar (which includes the federal tax credit) are offset by electric system benefits and greenhouse gas reductions.  Energy provides another 5-6 cents.  Presumably, state incentives (the CSI, net metering, etc.) fill the gap.

This next chart of interconnection costs for distributed solar has two interesting findings.  First, interconnection costs (for the utility) are lower for residential solar than for other small-scale (< 1 MW) distributed solar.  Costs fall off as projects increase in size to a sweet spot of 3-5 MW and then rise again.  Divided over the projected output over 25 years, however, these costs are in the hundredths of a cent per kilowatt-hour. Read more

1. Electric cars have arrived, but the pace of adoption will be slow.
2. There are several different types of cars that plug in, and their electric ranges vary.
3. In the early years, most charging will be done in garages attached to private homes.
4. You have to consider where and how you use your car(s) if you consider buying electric.
5. Electric cars are cheaper to “fuel” per mile than gasoline cars, and they have a lower carbon footprint too—even on dirty grids.

by John Voelcker, via the Rocky Mountain Institute

(1) Electric cars have arrived, but the pace of adoption will be slow.

Last year, roughly 17,000 plug-in cars were sold in the United States—more than were sold in any year since the very early 1900s. But to put that number in perspective, total sales in 2011 were 13 million vehicles, meaning that plug-in cars represented just one-tenth of 1 percent. Sales this year will likely be double or triple that number, but it remains a stretch to reach President Obama’s goal of 1 million plug-ins on U.S. roads by 2015.

Both the Nissan Leaf and the Chevrolet Volt sold more units last year than the Toyota Prius did in 2000, its first year on the U.S. market. But 12 years after hybrids arrived in the U.S., they now make up just 2 to 3 percent of annual sales—and about 1 percent of global vehicle production.

Automakers are understandably cautious when committing hundreds of millions of dollars to new vehicles and technologies. They worry that a lack of public charging infrastructure will make potential buyers reluctant to take the chance on an electric car. Moreover, each factory to build automotive lithium-ion cells—an electric-car battery pack uses dozens or hundreds of them—costs $100 to $200 million. Battery companies will only build those factories if they have contracts in from automakers, who will only sign contracts to boost production if they can sell tens of thousands of electric cars a year in the first few years.

Eight to 10 years from now, most analysts expect plug-ins to be roughly where hybrids are today: 1 to 2 percent of global production, with highest sales in the most affluent car markets (Japan, the U.S., and some European regions). That translates to perhaps 1 million plug-in cars a year. There are, by the way, about 1 billion vehicles on the planet now.

The adoption of increasingly strict U.S. corporate average fuel-economy rules through 2025, however, will spur production of electric vehicles. And California has just passed rules that require sales of rising numbers of zero-emission vehicles, on top of the Federal regulations.

(2) There are several different types of cars that plug in, and their electric ranges vary.

The two main plug-in cars that went on sale last year, the Nissan Leaf and Chevy Volt, use somewhat different technologies, and this year will see a third variation arrive, the 2012 Toyota Prius Plug-in Hybrid. Each works slightly differently, and their electric ranges vary considerably, roughly proportional to the size of their battery packs.

The Nissan Leaf is a “pure” battery electric vehicle. It has a 24-kilowatt-hour battery pack (it uses 20 kWh) that delivers electricity to the motor that powers the front wheels for 60 to 100 miles. That’s it. On the plus side, this is the simplest setup of all, and battery electrics require very little servicing beyond tires and wiper blades. On the minus side, if the driver is foolish enough to deplete the battery—the car makes strenuous efforts to warn against this—the car is essentially dead until it can be recharged.

The Chevrolet Volt is a range-extended electric vehicle. It has a 16-kWh battery pack (of which it uses about 10 kWh) that powers an electric drive motor for 25 to 40 miles. Once the pack is depleted, a gasoline “range extender” engine switches on, not to power the wheels but to turn a generator to make more electricity to power the drive motor that makes the car go. The 9-gallon gas tank provides about 300 more miles of range, and the Volt can run in this mode indefinitely. But 78 percent of U.S. vehicles cover less than 40 miles a day, so many Volts that are plugged in nightly may never use a drop of gasoline. Read more