apperson energy management

                                                           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.

                                                        SUN POWER

If you own or live in a home that is more than a couple of years old you may be paying more than you are comfortable with to heat and cool the place. As we’ve said many times here, up until just a few years ago not much attention was paid to the energy efficiency of a building, or how much it was going to cost to heat it or cool it. Our various forms of energy, whether is was electric or gas, were so inexpensive that it was cheaper to build homes with lots of infiltration and just throw in a larger furnace to compensate. And up until the 1970’s oil crisis that worked just fine. After that we started to realize that it does in fact cost money to change the temperature of the air around us, and some people started to look for solutions. The building codes started to change but that takes time and  now, forty something years later we are finally seeing building codes that force builders to construct homes that don’t waste as much energy. My point being we have a heck of a lot of houses that need help as far as energy conservation. We have a couple of good programs out there at present, and one in particular is very generous in that it is a low interest loan to help people make their homes more energy efficient, and one of the items you can borrow money to install to help your home is a solar system. We have been receiving a lot of questions about solar systems recently so I thought I’d pass along the little bit that I know about solar.
 
                                                           THE KINDS

When someone calls and says they want a solar system on their home the first thing we need to know is what kind they want. There are two basic types of systems that do two different things, both getting their power from the sun. The first kind and most basic and oldest is solar hot water. If you set a cup of water out in the sun to get warm you have a solar water heater. Some of the earlier systems used coils of plastic pipe run across a person’s roof which would get the water inside them hot as the sun beat down on them, and this was stored in a big storage tank. This was a pretty simple basic system with almost no moving parts. The obvious problem being if the system is not drained down in the winter the pipes freeze and bad things happen. And of course in our climate zone we don’t get enough sun to depend on solar to provide year round hot water, although I’m sure several solar guys would argue the point with me.. So the solar system is only used as a back-up to a primary system of gas or electric hot water. However, if you can get the sun to heat or even pre-heat your water for free (after purchase and installation cost) then it’s a bargain. The newer systems of course are much improved. The water no longer runs through the pipes on the roof. A fluid such as oil or an anti-freeze is used and solar powered pumps make sure the lines are drained when it gets cold and solar motors turn the panel array to follow the sun to capture every available photon. The panel designs have come a long way. The technology and improvements have made the new systems almost maintenance free, and panel size is such that a solar hot water and a solar photovoltaic system can both fit on the same roof of a standard sized home. And we still have rebates for the solar hot water systems, if you have an existing electric hot water heater the rebate can be substantial. But the Federal tax credits are the real inspiration, with a first year credit of 30% of the installed cost in a check back from the Feds. I’ve seen the first year tax credit and the rebate cover half the cost of a new system.

 These new systems have very few moving parts, I would think they would be good for many years, and with the 3% loan for 15 years that is funded through a CEC grant many people are taking advantage. If a person has the correct kind of roof, facing in the correct direction, and his neighbors trees don’t block the sun (or some arrangements can be made), a decent solar hot water system may make financial sense for a lot of people. But you gotta do the math.  Give it some thought and next time we’ll look at photovoltaic.