Wednesday, April 15, 2009

Net Metering, Why not Hydro?

I want to clarify the 'net metering' issue a little. I think that net metering is the most effective policy the government can implement to promote renewable energy derived from other sources besides solar & wind. If net metering were extended to all small scale (under 25KW) hydro sites, we would see a resurgence and interest in restoring thousands of small hydro sites that have been abandoned during the times of cheap oil. Many of these sites could be made productive again with lower investments because the infrastructure (dam, penstock, water supply) may still be intact. There is no valid reason to treat one renewable source any differently than another.

The advantages of a grid connection include vastly simplified control of frequency and voltage. Essentially the site runs wide open without any control and just pushes energy into the grid at the grid voltage and frequency. It is like you helping a freight train by pushing on the back of it. But you won't be able to change its speed at all, even if your efforts are doubled or stopped altogether, in other words, your energy input can fluctuate, but the train stabilizes everything just as the grid does for relatively small energy inputs.

The simplest way to get grid connected and reap these stabilizing benefits is through net metering.

Net metering is accomplished using a single-bidirectional meter, which is already in place on all grid connected homes. The newer electronic meters can be programmed to ignore the direction of the energy flow. Thus you can end up paying for the energy that you send to the grid! That way the power company keeps people from generating energy and turning their meter backward without their permission. ( Remember too, the days when Bell Telephone owned the phone lines and even the phones, and you could not connect your own! They made a ton of money charging a monthly equipment lease fee. So things will change in time with the power grid too.) The power company has to set (program) your meter to distinguish between energy coming or going.

I found this out the hard way when I first fired up our small (12KW) generator, synchronized it to the utility power line (grid), connected through a circuit breaker, opened up the butterfly valve controlling the power output and started really pushing that train. Then I sauntered out to the (electronic) meter on the pole and lo and behold the reading was increasing at a rapid rate! I could not believe that I was being charged for the power that I sent to them.

So now what can I do? Yes, I can get grid connected but only through an expensive switch which they have to approve. ( Remember Bell Telephones "approved communications interface"? ) And until I satisfy these interface switch gear requirements they won't reprogram my meter. They claim safety issues, (as Bell Telephone did up to the late '70's) But this is a red herring. If the grid goes down, (the train stops) there is no way that my 25KW is going to keep pushing that train ahead, and if it tries, any ordinary circuit breaker will disconnect me from the grid. The net metering of solar and wind energy requires little in the way of special disconnects either so why should renewable water power be any different?

So join me and lets have NET METERING FOR ALL RENEWABLE ENERGY be the law of the land! And while we are at it we should demand a favorable feed-in tariff for all renewables as well. More on that later.


RecycleBill said...

I agree entirely, the energy companies will fry every red herring they can fry to stop you from profiting from your ability to make money selling energy. For example: here in North Carolina, net metering only allows customers to sell back the same amount of energy we use-- no more.

I'll be back as I'm adding your blog to my blogroll-- lots of usefull info here.

Steve said...

When you are net metering, you are
being paid the tailblock or retail rate for your power. This is certainly a great benefit, but only if you develop an amount of power equal or less than your usage.
Development of small hydro happens with vigor when small producers are PAID the tailblock or retail rate for excess power, as happened in the early 80's after PURPA became the law of the land (and water).

Rodney Langley said...

Why not simply buy a couple of smaller, cheap solar panels and tell them THAT'S what you want the net meter for? After they put it in, just wire in your hydro system and call it a day ;)

Anonymous said...

@Rodney Langley, Way to go!

@Rob, I enjoy reading all of you're posts. I was wondering what you think of this unit for controlling my hydro plant, I talked to the guy that makes it and he'll customize it for my exact needs, control load ballast, deflectors, spear valve stoking etc..
It would be controlling a 75kw turbine for an off the grid farm

It's also on ebay

Rob said...

Rodney, a quick look tells me that this seems like an economical solution as long as you will not be grid connected. The utilities often have requirements, like UL listing, of devices that control the grid interconnection or inter-tie.