Solar Power for Your Home
| Solar power for residential clients can be a great solution to rising energy prices while providing a way to reduce your impact on the environment. Unfortunately, not every home is a good candidate for installing a solar power system. We believe that the most important service that we can provide is an honest assessment of the true potential for installing solar power at your home – and we simply won’t sell you a solar power system if we do not believe that it will work well for your particular situation. After all, we don’t just want satisfied customers, we want clients who are thrilled! (And they are – check out our testimonials, here.) |
|
There are two factors that determine whether your home would be a good site for solar – your current energy usage and the shading present on your available roof space.
Energy Usage and Residential Solar Economics
The first factor to consider is your electrical usage and the cost of electricity from your utility. It is always more cost-effective to reduce your energy consumption and most utilities, wisely, require you to investigate those possibilities first. For example, Pasadena Water & Power requires residential customers to take an online energy audit as part of the rebate application process.
As part of our design process, we will analyze your bills for the past year to determine the proper size for a solar power system. For SCE customers who are billed according to a tiered rate structure (that is, energy usage in the first two tiers is very cheap but gets progressively more expensive as you use more) the goal of a residential system should be to take you out of the upper tiers, thereby maximizing your savings without over-purchasing for your system. For customers billed under a flat-rate structure (such as PWP), every kilowatt hour costs the same, but often other charges – such as your customer charge – get higher as your usage increases.
At Run on Sun, we have developed sophisticated billing models for the utilities in our service area and we will use them to help you see what your true savings will be.
While historically prices per nameplate Watt have run between $8-$10 installed, we are starting to see residential prices move closer to $6.50-7.00/Watt and as low as $6.00/Watt for the larger residential systems. Of course, actual prices will vary depending upon the complexity of the installation, but potential clients should be very leery of bids above $9.00/Watt. When we provide you with a bid, we will explain it completely so that you will be able to make a true apples-to-apples comparison.
 |
Based on our experience, we believe that system sizes below 3.5 kW are generally not cost-effective, and unless there are exceptional circumstances present, we will not sell a system that is not 3.5kW or greater. For a system of that size, the Return on Investment is approximately 9% with payback in Year 10. As system size increases, so does the ROI thanks to the economies of scale. For an 8kW system, the ROI might be 13% with payback occurring in Year 7. |
If your monthly electric bill is $150 or more, please contact us so that we can design a home solar power system that will meet your needs.
Solar Pathfinder Shading Analysis for Home Solar Power Systems
All solar power systems are adversely affected by the presence of any shading on the solar panels, and that is even more of a consideration for home solar systems. Very few residential roofs are entirely free of shading, and a small amount of shading is acceptable. Unfortunately, many residential roofs have large amounts of shade that effectively rules them out as candidates for a cost-effective home solar power system. But how can you know in advance? We make use of a very simple, but elegant device, called a Solar Pathfinder™ that allows us to get a picture of the shading that will be present throughout the year.
Consider these two images:
The image on the left shows a site that is not appropriate for solar.
The tree shadows on the left-hand side will cause shading for nearly half the day, meaning that any system will perform poorly and the savings that the homeowner would be seeking from the system would likely never materialize.
Run on Sun would not sell a system to a client
with this degree of shading. Sadly, others will.
The image on the right shows an acceptable site.
While there is some shading, it is not significant enough to adversely affect the performance of the system and a conventional string inverter would be appropriate for this potential installation..
However, when roof shading appears to be only marginally acceptable we recommend using Enphase microinverters. With microinverters each solar panel is able to operate independently so the impact of shading is minimized.
We have been able to install several successful systems using microinverters that simply would not have been viable with conventional string inverters.
These variations in site characteristics call for differences in the equipment used as well. A completely un-shaded house that has plenty of roof space can take advantage of less efficient (but considerably less expensive) Suntech or Conergy solar panels in conjunction with SMA string inverters which will be the most cost-effective solution from day one. However, where shading is present (say somewhere between the two extremes shown above) or the amount of available roof space is limited, Enphase microinverters and/or the more efficient Sanyo solar panels may be required to produce acceptable results. We will work with you to produce a system properly designed to work with your house and your budget.
Premium of $6-7.70/watt!