Your Questions About Solar Energy Generators For Home

admin answers:

Simple answer, you need a multi-input grid-tie inverter.
My dad has one on his DC solar array. It can accept between 50 and 270 volts DC which is good for solar because he can wire them in series to add the voltage rather than parallel adding amperage which requires larger wires… Etc.
There are permanent magnet alternators you can order online that will produce pure A/C with no voltage limitation so you can control the output voltage via rpm governance. You could set things up to produce 120v A/C and tie directly in. You still need a grid tie device to protect your equipment and the grid.

Now the issue you will come into with an alternator generator is no control mechanism to compensate for load. Electrical generation is directly proportional to torque. If you put a heavy load on the system, it will become harder to turn which could slow down your rpms and in turn lower your voltage.

For this reason, alternators are typically used to charge battery banks which connect to an inverter.
You could wire a lot of batteries in series to get a higher voltage capacity and just rectify the A/C before it hits the batteries. Then you get a buffer allowing your alternators to have a range of output voltage which will give leeway for rpm fluctuation. And since the batteries will be a predictable load you really should have no trouble maintaining a steady speed.

Now I am guessing that you must have your driving force figured out. Generally speaking there is a direct conversion of horsepower to watts. 1 hp of torque will produce about 750 watts of power at top efficiency.
Steady water flow in a well designed system can easily exceed 40 hp in a single turbine which could drive several alternators. Steam is another good alternate fuel source. Solar concentration is often used to produce heavy steam generation. The trick is tuning the focus to achieve about 550 degrees or so, to get saturated steam. The down side is you only produce when the sun is out. I have an idea for combining these two concepts together. Use heavy solar concentration to turn the lower water pool into steam to lift it back to the top, while also condensing it through a turbine at the top. It’s a question of, how much sunlight will it take to move enough water that you have a nightlong supply running back down?
Seems like a major undertaking. It’s quite difficult to direct sunlight from a large array at a low position. Much easier to target the top of a tower.
Anyways, finely polished metal is the best way to reflect the most energy. I’m interested in building a smaller closes loop system for potentially scaling up. I’m wondering how high I can get the water via steam, and how many turbine stages it can fall through… In theory I can heat that steam continuously for hundreds and even thousands of feet of rise. Rocky Mountains are a good place to try that…
This kind of system could be ideal for property where there is ground water available but no naturally flowing surface water. You could even incorporate a distillery and fish pond, irrigation, etc.

I can’t divulge my ultimate experiment that this ties to. I think I figured out a way to store energy even better than batteries and raised water tanks.

admin answers:

It makes a big difference where you are located, what resources are available, if you are working with new construction or renovating old existing work.

In general, any path to energy independence is going to start with conservation. With heating and hot water this may mean point of use heaters, insulation, heating surfaces instead of the air (radiant heating costs less in operation) ventilation instead of air conditioning, earth tubes etc. Start to satisfy your existing 100% of current energy demands you may be able to achieve 20 to 30% with conservation techniques.

We feel warmer if surfaces are warmed than if only the air is warmed. It is more efficient as the surface temps can be 10 deg lower than we would normally heat the air. Radiant heating in floors and sometimes walls works well with both solar thermal panels and geothermal as a heat source.

In new construction a masonry stove (not cast iron) can be a very efficient use of wood. It may be lit once per day to a very high heat. The balance of the day and night the massive masonry structure radiates heat to the dwelling.

Geothermal, ground source heat pump applications are a kind of alternative form of heating conservation. It saves heating costs but still requires some energy. It does not yet supply more than it requires.

Solar thermal is 60 to 80% efficient vs photovoltaic which is only about 8 to 22% for the homeowner. There is some speculation that solar thermal plus a stirling generator may be several times cheaper than photovoltaic panels for producing electricity. ($1/ watt vs photovoltaic $5/watt.) Heat is also easier to store than electricity. So store heat to make electricity. Solar thermal comes in several designs for residences. In new designs it is in passive solar heating. For both new designs and retrofits a solar sun room may provide additional heat. Solar thermal systems can active or passive. Active systems have pumps. Solar thermal panels can be flat plate or vacuum tube collectors water based collectors or air collectors that have no liquids in them. Solar thermal energy can be used for heat, hot water, air conditioning and to generate electricity with a mid temp range stirling engine/generator.

It also would be possible in more rural settings to generate your own natural gas with a bio digester. It would however require massive amounts of bio fuel. However if the supply exists it is certainly a possibility.

While wind turbines are a possibility for electrical energy there is the duel problem of having power when you need it. First the wind must be blowing with sufficient strength and secondly there needs to be some type of energy strorage capacity. This storage shoud have deep cycle capacity. Heating water or a phase change material may be one option. Chemical storage may be another (hydrogen) Pumped hydro may be practical in some locations. There is some discussion of using compressed air for storage. This might give a byproduct of heat that could be used to some benefit. Otherwise we are left with batteries.