MORE SUN POWER
Last time we were discussing solar hot water systems and a little bit on how they worked and the rebates available for them. The other kind of solar system available is the solar P.V. or Photovoltaic system. If anyone should care about such things, “Photo” is from the Greek word meaning light, and “voltaic” refers to “volt” a unit ofelectromotive force.Turning solar energy into an electrical charge was discovered by a guy named A.E. Becquerel back in 1839, although there wasn’t an actual “solar cell”until someone named Charles Fritts coated some seleniumwith a thin layer of gold in 1883. The efficiency of this cell was 1%. The concept really didn’t go much of anywhere for quite some time as there just wasn’t any reason to develop a product that took in sunlight and produced electrical power. They weren’t very efficient and the batteries of the day weren’t much better. And besides about the only thing people were using portable energy for was for lamps to light their homes, and we had whale oil for that and what the heck, we had an unlimited supply of whales, right?
TELSTAR
It was the space race and our communications satellites that really gave the solar industry the jump start it needed. Bell labs developed the first modern solar cell in 1954 and added them to their Vanguard and Telstar satellites. We take it for granted now, but up until that time they would launch a satellite and it would run until… the batteries went dead. And then that multi million dollar piece of equipment was just abandoned, because it had no more power.
But that was the start the industry needed and, like computers, the price and function started getting better exponentially every year.
The way a solar panel works is a sheet of material is exposed to the sun. There are various materials, most have long, hard expensive names, and somehow silicone is involved. These sheets of materials are made into panels and protected by glass. The silicone based materials have impurities, and when the sunlight strikes these impurities they react by giving off a small electrical charge. Not much by itself but if you are able to multiply that many, many times as you do when you have a whole sheet in a panel, you have something that generates a usable amount of electricity. And it generates direct current or D.C. Direct current is not what you use in your home. D.C. is what you use in your car. Direct current always flows in one direction. A/C or alternating current alternates, and changes direction. It alternates and changes direction and flows back to the power plant, and it does this 60 times a second, and no, I have no idea how it does this or why.
So, in order for the D.C. power to be usable in your home it must be converted to A.C current, and trained to change directions very quickly, as noted above. The thing that does this is called an “inverter”. These are a very important part of the system and if they fail the system can not function. My understanding is the latest inverters are mounted with, or can even be part of, the panel itself and have become very dependable.
OFF THE GRID
The last component of the system are the storage batteries. If you are completely “off the grid” you will need storage batteries to store the excess power so you can use it when it is needed. Such as at night or when the sun isn’t shining or when you are using more power than you are producing at that moment. If you are a utility customer you can use the power company as your storage battery. Your electric meter will actually run backward as you feed power into the public grid and then reverse as you use more power than you produce. Once a year they “settle-up” and you either pay what you owe or they will pay you if you have produced and put in more power into the public grid than you have consumed. I don’t know about the City of Ukiah, but the rate that PG&E pays ($.04 kwh) is about one third of the lowest tier they charge their customers. But they still offer a rebate, and the Feds still have the 30% tax credit and the City of Ukiah still has their rebate which, last I heard was at $1.96 kwh, so you can still get a large portion of a solar P.V. system paid for. Then there are the year after year energy savings and I believe tax credits out a number of years. Something else you need to consider, smart meters. We are all getting one and that can mean “time-of-use” billing. That means on those 11 hottest days of the year, during the hot mid-day hours, you’ll either be paying a super premium to run your A/C or you are not going to be running it. The cool people will have solar.
Last time we were discussing solar hot water systems and a little bit on how they worked and the rebates available for them. The other kind of solar system available is the solar P.V. or Photovoltaic system. If anyone should care about such things, “Photo” is from the Greek word meaning light, and “voltaic” refers to “volt” a unit ofelectromotive force.Turning solar energy into an electrical charge was discovered by a guy named A.E. Becquerel back in 1839, although there wasn’t an actual “solar cell”until someone named Charles Fritts coated some seleniumwith a thin layer of gold in 1883. The efficiency of this cell was 1%. The concept really didn’t go much of anywhere for quite some time as there just wasn’t any reason to develop a product that took in sunlight and produced electrical power. They weren’t very efficient and the batteries of the day weren’t much better. And besides about the only thing people were using portable energy for was for lamps to light their homes, and we had whale oil for that and what the heck, we had an unlimited supply of whales, right?
TELSTAR
It was the space race and our communications satellites that really gave the solar industry the jump start it needed. Bell labs developed the first modern solar cell in 1954 and added them to their Vanguard and Telstar satellites. We take it for granted now, but up until that time they would launch a satellite and it would run until… the batteries went dead. And then that multi million dollar piece of equipment was just abandoned, because it had no more power.
But that was the start the industry needed and, like computers, the price and function started getting better exponentially every year.
The way a solar panel works is a sheet of material is exposed to the sun. There are various materials, most have long, hard expensive names, and somehow silicone is involved. These sheets of materials are made into panels and protected by glass. The silicone based materials have impurities, and when the sunlight strikes these impurities they react by giving off a small electrical charge. Not much by itself but if you are able to multiply that many, many times as you do when you have a whole sheet in a panel, you have something that generates a usable amount of electricity. And it generates direct current or D.C. Direct current is not what you use in your home. D.C. is what you use in your car. Direct current always flows in one direction. A/C or alternating current alternates, and changes direction. It alternates and changes direction and flows back to the power plant, and it does this 60 times a second, and no, I have no idea how it does this or why.
So, in order for the D.C. power to be usable in your home it must be converted to A.C current, and trained to change directions very quickly, as noted above. The thing that does this is called an “inverter”. These are a very important part of the system and if they fail the system can not function. My understanding is the latest inverters are mounted with, or can even be part of, the panel itself and have become very dependable.
OFF THE GRID
The last component of the system are the storage batteries. If you are completely “off the grid” you will need storage batteries to store the excess power so you can use it when it is needed. Such as at night or when the sun isn’t shining or when you are using more power than you are producing at that moment. If you are a utility customer you can use the power company as your storage battery. Your electric meter will actually run backward as you feed power into the public grid and then reverse as you use more power than you produce. Once a year they “settle-up” and you either pay what you owe or they will pay you if you have produced and put in more power into the public grid than you have consumed. I don’t know about the City of Ukiah, but the rate that PG&E pays ($.04 kwh) is about one third of the lowest tier they charge their customers. But they still offer a rebate, and the Feds still have the 30% tax credit and the City of Ukiah still has their rebate which, last I heard was at $1.96 kwh, so you can still get a large portion of a solar P.V. system paid for. Then there are the year after year energy savings and I believe tax credits out a number of years. Something else you need to consider, smart meters. We are all getting one and that can mean “time-of-use” billing. That means on those 11 hottest days of the year, during the hot mid-day hours, you’ll either be paying a super premium to run your A/C or you are not going to be running it. The cool people will have solar.
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