SOLAR TODAY Blog


>>NY’s Cuomo compels Xcel to disclose climate risks
August 28, 2008, 8:39 pm
Filed under: Fossil fuel, Utilities

New York’s attorney general Andrew Cuomo reached an agreement Wednesday with Xcel Energy, under which the multi-state electric utility company will disclose to investors the financial risks of climate change and carbon-emission compliance.

It’s the first agreement of its kind, and may greatly increase the costs of financing new coal-fired power plants.

According to The New York Times, Cuomo’s office is now negotiating similar agreements with four more large electric utility companies.

If these agreements become common practice, Wall Street investors will think twice about investing in coal plants. It may be another nail in coal’s coffin.



>>Yamavolt progress
August 22, 2008, 6:16 pm
Filed under: Electric fun

The sprockets and batteries are in. I bolted up the big custom-made 72-tooth rear chainwheel and it’s a perfect fit. There’s barely enough clearance for the chain to pass the rear shock absorber spring, so I’m going to fiddle up a set of bushings for the shock mounting, to move the whole unit outboard about a quarter inch. The 13-tooth power sprocket is another matter. It’s a standard Yamaha part made to fit the output shaft of a Yamaha transmission. I dropped it off at a local machine shop to get it mated to the electric motor output shaft. The shaft needs to be turned down and the sprocket bored out to match. Then I need a collar with a set-screw to hold the sprocket in place. This is far more expensive than just boring out the sprocket and spot-welding it in place, but it will allow me to replace the sprocket to play with the gearing.

The four 12-volt 18-amp-hour batteries arrived in one 50 lb. box. Over the weekend I’ll start building the framework to hold them, and wire them up to the controller and throttle. In theory, late next week I’ll be able to slide the motor back in, hook up the drive chain and cables, and ride off into the future.



>>Roofray guesstimates solar potential
August 18, 2008, 6:12 pm
Filed under: PV technology

Want a quick, rough estimate of how much solar power you could generate on your roof or in your yard?

Roofray.com is a cool mashup of Google Earth with a solar power analyzer. Enter an address and you get a satellite view of the property. You can then select a portion of the roof or yard to take a solar array, outlining the system by clicking on its corners. And you can specify the array’s angle to horizontal. Using climate data for your latitude and longitude, the website then quickly calculates the square footage of the array and its maximum theoretical power capacity. It told me, for instance, that my garage roof could support enough PV to max out the local utility-company rebate.

One nice feature here is that most Google Earth satellite photos are taken near mid-day, so as to minimize tree-shading on rooftops. This means you can draw your array in the sunniest part of the lot, or see what trees might have to be pruned in order to maximize sun on the roof.

The system won’t design your solar system for you, but it will give you some ballpark figures to play with, and let you know whether it makes sense to take the next step.



>>PGE&E contracts for world’s largest solar array
August 15, 2008, 2:44 pm
Filed under: Utilities

California utility Pacific Gas & Electric has announced plans for two massive PV arrays, totalling 800 megawatts, in San Luis Obispo County. Under power purchase agreements, OptiSolar will build a 550 MW thin-film array, and SunPower will build a 250 MW silicon system.

Together, the two arrays will produce 12.5 times the power of the largest existing solar plant, the Nevada One concentrating solar thermal facility in the Mojave Desert. PG&E hopes to have the new capacity come o online in stages from 2010 to 2013, some of it in time to help meet a 2010 deadline for 20% renewable power under California’s RPS. The company says it will produce 24% renewables by 2013.

The deal depends on federal and state permitting, construction of new transmission lines, and on renewal of the 30% federal investment tax credit, still stalled in Congress.

For more detail see stories in the San Francisco Chronicle, San Jose Mercury-News, and New York Times.



>>Yamavolt: Motor in
August 13, 2008, 2:49 am
Filed under: Electric fun

I ran the plywood pattern for the motor mount over to a welding shop and they cut the two plates from quarter-inch aluminum sheet. They plates bolted up perfectly to the frame with 8mm bolts. I rolled the motor into place and snugged it down with a long hose clamp. I chose this motor in part because its outside radius is a perfect match for the radius of the original steel motor mount plates — my aluminum cradle simply extends that radius forward to link up with the downtube. I’m going to bolt a short flat link to the left face to keep the motor from torquing under acceleration — and regen deceleration. The link will also locate the motor mass laterally.

All the parts are here, save the sprockets, batteries and cables. I’ll round those up this week and bolt up a framework to hold the batteries, using aluminum angle stock. The “lightening holes” in the motor mount arms are really there so I’ll have someplace to fasten the bottom end of the battery support — and also a way to bolt on a kick stand. Because the motor hangs out on the right side of the bike, I’ll cant the batteries a bit to the left for balance.

On Thursday I ordered the chain and sprockets. The rear chainwheel is a huge 72-tooth custom-made pizza platter, but it will slip right onto the rear wheel with the original four-bolt pattern. The drive sprocket is a more-or-less standard size 13-tooth Yamaha item but I’ll have to drill out the splined center hole to fit the 7/8″ keyway electric motor shaft.



>>Yamavolt project: Motor mount mockup
August 9, 2008, 6:21 pm
Filed under: Electric fun

The D&D golf cart motor arrived this week, along with the Alltrax controller. The motor weighs 38 lb. I cut a cardboard pattern for a set of motor mounts, transferred the shape to half-inch plywood, and bolted it up. Here’s what it looks like: nice, tidy package.

The next step is to duplicate the mounts in hard aluminum sheet, and get some chain sprockets made up. I’ll use 84 teeth on the rear wheel, which has an odd four-bolt hub-mounting pattern. The front sprocket goes on a 7/8-inch shaft with a keyway. I’ll use a 12-tooth sprocket to start, which ought to give me 49 mph at 4800 rpm — if the motor will pull it.

Still waiting on the Magura throttle, and I’ll start scrounging for batteries this week. Another project is programming the controller, so I’ll spend an evening figuring that out.

Click here for background on the Yamavolt.



>>Obama puts efficiency first
August 6, 2008, 3:50 pm
Filed under: Policy, Utilities

Sen. Barack Obama’s major energy policy speech on Monday hit a lot of the right notes.

A few high points:

He notes, correctly, that the most cost-effective way to reduce our use of imported oil — and fossil fuel generally — is to improve our efficiency.  We need to sharply reduce the rate at which we waste energy.

Accordingly, Obama calls for a 15% reduction in the use of electricity by 2030. This would save consumers $130 billion and create a lot of jobs.  How?  Part of the plan is to weatherize a million homes per year. That has to be done by local contractors and handymen, using building materials manufactured here in the United States. Part of it is to revise building codes, improving the energy performance of existing buildings by 25% and of new construction by 50% — again, using local labor and materials.

The federal government should lead the effort by reducing its own energy use by 25% over the next five years and by 40% by 2030.

On the utility side, Obama proposes decoupling utility company profits from the amount of electricity generated — “flipping” their business model to reward efficiency gains. To do that, they’ll have to adopt smart-grid technology nationwide, and he offers federal help to make the necessary infrastructure upgrades.

It was a good sensible speech. There’s hope.

Read the transcript here.