charging electric cars without an inverter

[billvon]

Is anyone familiar with any systems that will let you charge an electric vehicle (i.e. Nissan leaf) directly from pv panels?

Another thought on how you could approach this:

Install a commercial (say 40kW) system at a local shopping center. Wire it in strings such that Vmpp is around 450 volts and you end up with 8 5kW strings. (This is a common target voltage.) Wire all of them to a commercial 40kW grid tie inverter (or bank of inverters, whatever's cheaper.)

When anyone plugs a car in, then one of those strings is switched from the inverter to a DC/DC that drops the voltage from 450ish volts to the 403 volts that the Leaf needs. A DC/DC converter designed to run at 90% duty cycle is relatively cheap and easy to design. While the car is plugged in, that string is dedicated to that car. When it is removed, the string is returned to grid tie operation.

[Sunking]

[...] A good power pigtail cost a hundred dollars and electricity is dirt cheap. Spend $120,000 to make $2 worth of electricity per day for an EV [...]

[billvon]

Bahwhahaha. You sure like spending others people money and wasting it. A good power pigtail cost a hundred dollars and electricity is dirt cheap. Spend $120,000 to make $2 worth of electricity per day for an EV . I know who you are voting for.

Your political rants are cute, but to the point -

My company has installed about 400kW of solar. We do a lot more with it than "making $2 worth of electricity." One of the things we do with it is convert the 500VDC to 480 volts AC via GT inverters, convert that to 240 volts via a local transformer, then convert it back to 400 volts DC to charge all the EV's we have. (We're planning to support around 100; right now we're at 21 charging stations, which supports about 60 cars total.) That's around a megawatt-hour of power a day that goes through all those conversion steps. Being generous and assuming a 90% conversion at each stage (95% for the transformer) that's 250 kilowatt-hours of power wasted every day, or about $9000 a year wasted.

[...]

[billvon]

I am not anti-progress now. I was when I was a left winger in college protesting nuke plants and sabotaging the Forrest industry. Bu tI put th eBong down and went to work for a living. I am all for development, just do not force me to where my money is going and let the Market decide where it goes.

The market is a great thing to apportion consumer goods and services to consumers, not so great when it comes to deciding national energy policy, public health, the survival of species, our foreign policy or requirements for fair competition. Leaving everything up to the market gave us Enron, Standard Oil, the Triangle Shirtwaist Company, the killer fogs in London, Donora, burning rivers in Cleveland etc. One of the things I learned _after_ college is that any extreme - pure capitalism, pure communism, pure socialism, pure democracy etc works about as well (i.e. not very well at all.) A wise plan does not worship any of those systems, and instead uses the best of each and rejects the worst of each.

You cannot stop or change the Market. It has always and will always make the decision.

How's Standard Oil doing these days?

I am an EV enthusiast and you know it.

Cool. People developing technologies and products for EV's and hybrids today stand to make a lot of money as improving technology drives wider adoption of those products. Primarily due to their marketability; hybrids are now standing on their own and selling in the millions. They got there partly due to help from governments (both Japan and the US) to get the technology over the barriers to entry. I think that's great - people have more choice nowadays, and with energy supplies getting tighter, choice is a good thing.

[russ]

Bill - I can not answer you in the manner you deserve - rules of the forum - but I have not often read such drivel.