What is the balkonkraftwerk 600w komplettset revolution? I hear people talk about it every day, but what is it? Is it even real? People rail against reliance on coal, fractal mining for natural gas, pumping oil to power our cars, the list goes on… It wasn’t but a year ago that the “Green Revolution” was upon us. Notice the “Revolution” term being thrown about. Makes it more exciting. How about the “Solar Revolution”? Is it upon us?
To put it plainly, yes the solar energy revolution is upon us, but probably not in the way you were expecting. The often touted solar revolution involves solar panels on every house and massive solar farms sprawling across the vast deserts of the world. I hate to be the bearer of bad new, as much as everyone would like, this will never be a reality.
The first issue is there are just not enough high sun intensity climates to make this a reality. In order to make solar power feasible, the location needs a majority of intense cloudless sunlight per day throughout the year. Most places get less than 8 hour of direct sunlight a day at any given time during the year. Without this direct sunlight the solar panel economies just don’t add up, which is key for adoption.
The second issue is not related to location but is something every location on Earth experiences, nighttime. Yes, half of our time is spent in the dark. While you might not notice, I guarantee your solar panels will notice. Until someone invents a solar panel that works in the dark, the best efficiency achievable on a solar power system is fifty percent, which does not even include solar panel efficiencies in the high teens. This is like buying a car which only runs half the time you want it to. A house that you can only live in half the time.
Our society is not structured to only use power during the daytime. We need electricity at night to power our lights, run our heaters and air conditioners, open the garage door, the list goes on… How do we store power for night time once the solar revolution is in full swing? No idea, this is not an easy issue to solve. How about massive battery packs? Nope, these are prohibitively expensive, the power density is low compared to power requirements and storage efficiently results in additional power loss. The cons simply out way the benefits.
Okay, how about a giant lake, we pump water into it during the day using excess electricity and run turbines at night to generate electricity? Now were talking! But wait, electric pumps are about 50% efficient at pumping water, and turbines are 90% efficient at turning that potential energy into power. That leaves us with as system 45% efficient.
Let’s do that math on this nighttime power storage. Solar cells 17% efficient. Solar systems 50% efficient due to nighttime (using a generous 12 hours of usable sunlight a day). Our giant lake storage system 45% efficient. This gives us an overall power efficiency of, wait for it, a whopping 3.8%. For every 100 watt hour of light put in, a mere 3.8 watt hours come out. You go from being able to power a standard (non California) incandescent light bulb, to being able to power a small LED key light.
