HOW WOULD YOU BUILD A SOLAR PANEL THAT CAN CONVERT SUNLIGHT TO ENERGY, JUST BEING ON YOUR HOUSE ROOF?

You have a couple of options.

The first option is to put together a flat plate collector to generate hot water. If you live in a cold climate, you might have to use evacuated tubes and this will probably blow your budget. The hot water could be used as a pre-heater for your existing hot water system. Complete systems for domestic hot water will not likely fit into your budget.

The second option is a small solar panel to generate electricity. In order to fit into you thousand dollar budget, you will need something like this:
1) an 80W panel. This will set you back about $400. You can’t make the solar cells yourself, so it is just as well to buy a complete panel.

2) A small solar charge controller for about $100. This will take the power from the panel and make sure your storage battery is properly charged.

3) An inverter. This will take power from the battery and generate 120 volt AC power (like your wall sockets). A 120W unit will be less than $200.

4) A 12 volt deep cycle battery, perhaps $120.

5) A transfer switch to cut the power when the battery gets discharged and transfer to 120 volt utility power.

You should be able to put it all together for $1000. However, you need to treat this as a hobby. The power you will generate is worth less than $10 a year, and is about enough to power a DSL modem and router (i.e. your internet connection). If it lasts 25 years, your investment (or loss in this case) will be about minus 9%. Of course, the battery won’t last that long, but the other parts could.

The actual power you can generate can be estimated from solar insolation maps. I will post a link below to a few that might help.

Collecting heat is probably more valuable (e.g. using a heat collector rather than a photovoltaic collector for electricity).

You can probably find plans on the internet for do-it-yourself flat plat collectors using plumbing parts, and electronic circuit diagrams for things like solar charge controllers, but I think this will be too complicated for your first project unless you really like tinkering. Buying components and integrating them yourself (figuring out how that get everything interconnected) will be loads of work for you first project.

Don’t be discouraged by the economics. You will learn countless things in the process and knowledge is always a good thing. Someday as prices come down on silicon cells (perhaps a new thin film technology) and evacuated tubes are made by the hundreds of millions you will be able to use your skills to make a much larger and cost effective system.

Have fun.