Some basics to help get started

SO, here is some information to help you get started with setting yourself up on solar panel power. Some things need to be taken into consideration when planning your approach to setting up a photovoltaic solar panel system. The following are options to think about when determining your solution:

1. Supplementary tie-in solar panel system to offset part of the utility power that is consumed.
2. Tie-in solar panel system that offsets all utility power consumed. This works by installing a system that produces more power than is consumed during the daylight hours in order to offset the power consumed from utility during the dark hours. The previous blog is an example of this solution where approximately a month's worth of reserve power was produced over the course of a year to provide for potential extra cloudy weather. This solution does not provide backup power when utility goes down during dark hours.
3. Tie-in with battery backup. This solution could be a combination of either solutions 1. or 2. above with the addition of a battery bank such that when utility drops out, your house will still have power available for X hours until your batteries run down, utility comes back on, or sunlight energy is available through the solar panels.
3. Off-grid. This solution usually requires a battery bank since the house is run entirely off of solar panels with no tie-in to utility. The battery bank will need to be substantially larger than the other solutions in order to maintain power for your home during the dark or stormy hours. This solution can be more costly up front due to the addition of a larger battery bank.

Now, all of these options considered, if the desired solution involves a utility tie-in, then an inverter needs to be selected. The size or capacity of the inverter needs to be determined based upon your final goal of supplementary or full utility offset. If your goal is to offset all of your utility power by over generating during the day and using utility during the dark hours, then the inverter needs to be sized according to that daytime power generation. For example lets say you only want to spend $4k-$5k initially. Inverters can be purchase anywhere from $1k to $2k and on up. But for a typical house as described in the previous blog. Five bedrooms, three bathrooms, great room, dining room, kitchen, office on gas heat, a 3.3kW system is adequate for full utility offset power generation. So since the goal is full offset of utility power usage, a 3.3 or larger inverter needs to be purchased initially regardless of how many panels are initially installed. I think I have found 200 Watt panels in the $450 range. So, a person could purchase 4-6 panels and an inverter in the $1k-$2k range and keep their budget in that $4k-$5k range and generate 800-1200 Watts of power in good sunlight. That's 24% to 36% of total usage generated with the solar panels without spending as much up front. Then each year, or whatever budget plan is established, more solar panels can be added to your system to offset a greater percentage of power usage. Keep in mind that in LPEA district, the credit offered is based upon the initial hardware and installation cost. So, if you spread your cost out over a few years by "piece-mealing" your system. You won't get rebates for the expenses following the initial installation. I'm not sure how the Federal Tax rebates work. However, we have to work with what each of us has available to us.

If your goal is just to offset part of your utility usage then determine what amount that is and size the inverter appropriately. If you want to offset half of the utility power that you use then based upon this example of a 3.3kW system, you will need a 1500-1700kW inverter. The good news is that the inverter cost does go down somewhat with the lower power rating. The websites that I included in previous blogs have a few inverters to choose from. Sunny Boy seems to be one of the more popular brands in my research experience and when talking with people who have done installations. Your initial installation may not have sun tracking. This will cut down on your initial installation cost but bear in mind that your power generation may be up to 50% less than it could be as a result. Since solar power coupled to a house now adds resale value to the home. It may be easier to get a home improvement loan for those who are able to do so and installing a complete system from the beginning is an option. With the solar system offsetting your utility bill each month, that extra money can be redirected towards paying off the home improvement loan.

I believe the installation time and cost can be kept to a minimum with some simple design considerations. Based upon what I have researched, I think a two pole breaker can be added to the existing breaker panel in the house and a 14 gauge two conductor outdoor power line run from the new breaker to the solar panel system. The inverter can be located with the solar panels which permits the lighter gauge wire run from the house to the solar panels. If the inverter must be installed away from the solar panels then much heavier gauge wire carrying DC power must be run from the panels to the house and the wiring cost will be considerably more. Just a rough estimate of cost difference is say $150 -vs- $600, or more depending upon the length of the wire. Those are very rough numbers just to use as an example.

I don't know if this information helped. But,hey! It was free!
Have a great day!
James