One of the new ‘en vogue’ ideas to save the planet has been to install residential renewable electric generators to one’s home with the idea to sell some of the excess energy back onto the grid. Many states, including Kansas, has adopted the idea with a net metering solution. That is to say, using a meter to works both forward and backward. If the residence uses a kWh then they are charged for a kWh, but if it generates a kWh that isn’t used in the home they can sell it back on the grid and the meter moves back one kWh.
That’s a pretty neat idea, right? Each home can have a little windmill or solar-panel just pumping out CO2 free energy and the people of the home can make a couple of bucks and sell electricity to their neighbors! That’s really cool, until you think about it.
There is two problems with this, one is for all the residential generation and the other is more specific to the net metering solution. I’ll address the net metering first.
When one uses a net metering solution, in essence, they are selling electricity for the same price the utility is. But, they aren’t providing the service the utility is. Much of what goes into your utility bill covers not just the cost of the energy to the utility but also the wages for humble slaves such as myself and linemen etc. Also, it covers the cost of maintenance. What many people don’t realize, is that maintenance and upgrade is a never ending process. Equipment wears out. Oddly, even the line itself wears out. Normal contraction and expansion of the metal due to temp changes and wind tends to stretch the line. After a while, the line will no longer conduct electricity in the proper manner because of the sizing changes. Businesses and residential loads change and move. Often, this means that the type and size of the conductor isn’t proper for the load change, so, it must be replaced from time to time. Poles rot and have to be replace, trees grow into the line, and so on….. All of this costs a lot of money. So, when a person sells back electricity to the utility at the same price as the utility is selling it, the utility is taking a huge loss per kWh sold to it. If this novel idea become prevalent and widely adopted, utilities will go broke, and then there won’t be a grid to sell energy back to. It is an insidiously stupid idea.
But, what if we don’t adopt a net metering solution and meter separately the in and out energy and sell back to the utility somewhere closer to what the utility pays their provider? That wouldn’t be bad, would it? Well, maybe not. Sort of. But, the problem with this gets just a little more complex. The problem with selling energy back from residential is that the large generation plants can’t plan or gauge how much they will generate. For solar panels, they generate throughout the day. But, most of the day time consumption is base load consumption. The peak doesn’t happen until towards the end of the day and into the evening. So, what occurs is that the heat generated is wasted. So, for solar, there is very little net gain, and it doesn’t even do what the greens want it to……. it doesn’t reduce CO2 emissions. It simply lessens the the total reimbursement for generation. In other words, as a whole we get less bang for our buck. The problem with residential wind generation is similar. Even though wind doesn’t really have time boundaries such as solar, it is much less consistent. So, the generation plants, in order to ensure supply of the demand still generate the necessary electricity. So, any residential wind energy sold back to the grid doesn’t do anything other than waste energy generation.
When considering these posits, it is important to remember, with electric generation and consumption there are two different events that can cause very bad things to happen. One, would be the occasion that if supply doesn’t meet demand. This causes blackouts. Conversely, if supply of electricity on the line actually exceeds demand, things will go boom. The energy has to go somewhere.
To summarize, the residential generated electricity sold back to the grid isn’t conserving much of anything. Nor, does it reduce emissions in any measurable amount. But, we do subsidize these things quit nicely. Turns out, instead of saving us anything, we get to pay for some of our electricity twice! Kinda gives you a warm fuzzy, no? 😐