What is the solar 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 energy 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.
Don’t get me wrong. We will implement massive solar systems and panels on a few neighborhood roofs, but nothing nearing power requirements. These systems will supplement the power grid, not drive the power grid.
But wait, I thought the solar revolution is upon us? Well it is, but not in the way you might expect. The future of solar power are small scale systems where the initial cost of implementation is tiny in comparison to connecting the same system to the power grid. These are most often rural and isolated areas. Areas where the cost to install a power cable can be in the tens of thousands of dollars, but the cost of a complete small scale solar system is in the low thousands.
Solar panels costs have been decreasing rapidly, brushless motor technology has advanced with the help of efficient low cost motor controllers. These technologies cost thousands of dollars merely a decade ago, now can be acquired for much less. Rural locations can now take advantage of these technology advances to install small scale isolated solar power systems, saving thousands of dollars a year.
For the last century these rural environments have taken advantage of other technologies for rural locations such as wind and gas generators. Just think of the windmills scattered across America pumping water in windy weather for cattle drink and the people bath in. The future for these locations is small scale solar.
Sunlight is a power source that supplies electrically for about 8 hours a day in most climates. While for our massive power grid, this was a negative, for our rural location this is a positive. 8 hours of power for most systems will results in great performance. Let’s look at a solar power well pump system.
A solar powered water pump which pumps only 2 gallons of water a minute, which can be accomplished by a very small pump, will produce almost a thousand of gallons of water a day. This is enough for the average family or at least a hundred head of cattle. And the cost? The cost of one of these small scale systems is a few thousand bucks, at least an order of magnitude less than trying to tie into the power grid.
Take a small step up to a mid-size system which produces about 5 gallons per minute and the system will produce 2400 gallons per day. This will support almost 240 head of cattle, or supply a family with all the water they could possibly use. How much does this water cost on an ongoing basis? Nothing, zero, it is completely free.
This is the future, this is the “Solar Revolution”. Technology advances are enabling these small scale systems to perform tasks only limited by the imagination. Tasks not possible only a decade ago, are commonly being performed today. Pumping well water in a isolated location? No problem, just install a solar power well pump in a single weekend. Need water pumped from a pond into a storage tank? Not an issue, solar power surface pumps are readily available.
Yes, technology has enabled the “Solar Revolution”, but not in the way most people think. Small scale systems have been and will continue to show up all over the place at in increased rate. These are often small, low key systems which require a keen eye to spot. Keep an eye out for them. You will be surprised on how many you start noticing.