We’ve heard a lot about renewable energy. We are told that wind and solar panels should power our future. There was also a time when we were told that we would someday have flying horses as we trained horses to run faster and faster. Sure, that sounds nice, but I wondered if the pieces of the green energy puzzle really fit together and worked. If you look closer then you’ll immediately see that wind is unreliable, with too much wind at one moment and too little or none at all the next. Solar power doesn’t work well on cloudy days and it clearly doesn’t work at all at night. Since we don’t want to sit in the dark, the obvious way to store power is to put electrical energy into batteries. I couldn’t find good articles on how large, how durable, and how expensive that would be. I didn’t see reports on pilot projects to make “renewable” power reliable and usable. Are batteries going to become better and cheaper tomorrow? What I found says that batteries will never convert solar and wind into reliable, large-scale, affordable energy sources. I hope I’m wrong, but this is what I found using high school math.
The need is obvious. We want to light and heat our homes at night. We want to cool our homes during the day. We want to power our factories and our offices around the clock. We want to prepare our meals and store our food all the time. We want to have running water and a functioning waste system at every hour of every day without interruption. Bad things happen to us when we are powerless.
How much power do we use today? The University of Michigan gives us a good first estimate. They said that each of us uses about 12 thousand watt-hours per day at home. We’ll need five times more when we add in commercial, industrial, and transportation uses of energy.
That 12 kW-hr estimate doesn’t capture all the energy we use today. Today, we also use coal, oil, and natural gas. Those sources of energy are not available in the utopian green future. As President Biden said, no more drilling. We will have to be enormously more efficient to do everything we want to do with only 12-kW-hr of electricity per person, but let’s start there and see what happens. Recreational vehicles, boats, and remote cabins use batteries, so let’s see what we need to turn solar power and wind into useful energy at home.
A large lead-acid battery today gives us 100 amp-hours at 12 volts. The battery can give us more, but then it degrades quickly and it won’t take a charge over and over. We derate the discharge level so the battery system will last at least four years before we have to replace it. Four years of use requires about 1400 nightly discharge cycles. We also want to have enough battery storage to last four days when the clouds obscure the sun and the wind doesn’t blow. That doesn’t cover every cloudy and still weather event, but it is a start.
Just as I’m not counting the gasoline for our cars and the natural gas to heat our homes, I’m not counting on an extremely cold or an extremely hot day when our energy use is much higher. So far, we’re only looking at the energy we need for four average days of electricity. We may want to have more.
Once you do the math, it means we’re talking about 5,120 pounds of batteries per person at home. The battery and their charging and discharging system fills a 10 by 13 foot room per person. The batteries cost about 15 thousand dollars per person, but that is simply the cost to buy the batteries.
We are ignoring the cost of the charging system that puts energy into the batteries. We didn’t count the discharging system that converts low voltage battery power into the AC power we use in our homes. There are energy losses when we put energy in, when the batteries sit, and when we take energy out, but we are not counting those yet.
We’re ignoring the cost of the building space required to house the batteries. When we add those in, we are looking at numbers more like 30 thousand dollars per person. Since the batteries only last about four years, we also have to budget an additional 600 dollars per month to replace components as they age.
None of that includes the cost of the wind turbines or the solar panels that produce the “green” power we need. We are simply adding up the cost to convert intermittent power sources into something we can use at any time. The cost of disposing of the batteries and recycling some of their materials is extra too.
You can argue that businesses need power too so we won’t have to pay for all these batteries ourselves. That is both true and false. It is true that businesses will pay more as energy gets more expensive. It is also true that we will pay higher prices when we buy products made with green energy. What we haven’t asked is if 30 thousand dollars per person for a battery system and an additional $600 dollars a month is affordable to power our homes.
The median US citizen has about $2,000 in an emergency fund and a total of $3,500 in savings. Half of us have less. A quarter of us don’t have any savings at all and they are living paycheck to paycheck. On average, our savings would pay the battery-bill for half a year. For most people, going green means living with their parents for another decade or two.
These huge energy costs also put most businesses out of business. That works for China, but it doesn’t work for me.
We discovered electric batteries about 242 years ago in the year 1800. We’ve been looking for a better way to store electricity ever since. We are unlikely to find batteries that are ten times cheaper and equally efficient any time soon.
Depending on that magnitude of breakthrough is wishful thinking. Looking at these costs also explains why there are no large-scale demonstration projects for battery storage. It is more politically useful to pretend that intermittent “green” energy is worthwhile than to demonstrate that it isn’t.
I gave you 900 words. Please share them with a friend and leave a comment.
Deep cycle battery- https://www.renogy.com/deep-cycle-agm-battery-12-volt-200ah/
US residential energy consumption- https://css.umich.edu/publications/factsheets/energy/us-energy-system-factsheet