Solar Site Surveying

Let WayneDesign perform a Solar Site Survey for your Home, your Solar Photovoltaic Panels, Solar Hot Water placement, Solar Heaters, your Organic Garden Location, or Greenhouse. Solar Site Surveys include computer generated documentation you need for saving you money from both the initial purchase of your equipment to the actual incentives that are available for your location. Go here to see what incentives are waiting for you: http://www.dsireusa.org/.

The Solar Site Survey
A solar site survey is used to answer several questions for a potential buyer of solar electric equipment:

1) is solar electric feasible for the particular property, and, if so,
2) where should the equipment be optimally placed, and
3) how much equipment can be accommodated

A Solar Site Survey is performed at the prospective physical location of the potential buyer. Various measurements are taken to determine where solar insolation can be maximized, taking account of various surfaces, their pitch angles from horizontal, and obstructions. An "image based" approach is used to illustrate where the solar modules should be placed. These images and parameters can be used to inquire about price and delivery options from qualified solar installation vendors and/or for Do it Yourself consideration. An added feature is an illustration of solar system size showing anticipated energy generation in kWHRS. A narrative is included noting various financial subsidies from State and Federal sources that can effect both the system sizing and financial worthiness of the solar investment.

Economic proposition of solar electric
In many cases, buying a solar electric system at retail without State and Federal incentives to reduce the capital or generation costs is currently a poor value proposition and is likely to remain so in the short run. There are several exceptions including DIY systems which have good value even with limited financial subsidies but they require some installation skills, know-how in various Permit and Approving authority Codes and self-confidence in integrating a diversity of components. In the long run all solar cell/panel costs will continue their long term decrease (experience curve) as electric rates rise so what may not appear economically attractive for a buyer today inevitably will be cost effective at a future point.
Lowest Evaluated Cost should be the key objective in a solar electric system buy. Lowest Evaluated Cost considers many factors like initial cost, product warranty, module and mounting type, time value of money to compare financial returns and financing considerations. In some cases, the best acquisition option may not be system ownership at all but a lease-like approach.
There are also times when a buyer may want to pay more for their solar equipment than an apparent equivalent. Perhaps the modules need be on the front street facing roof and the consumer desires a more aesthetic appearance, at a price premium. Or perhaps, spatial area is limited so more productive premium priced solar modules might be more desirable to achieve greater power from limited space. In some case 'less' productive modules of a different technology might also make sense where there is an abundance of space. For example, film type panels are less efficient and cost less per watt but may have greater installation costs. Tradeoffs abound!
Government subsidies are needed to make solar electric financially worthy.. the State of NJ, for example, has targeted a current dollar capital payback of about 10 years. What a buyer actually 'achieves' in payback terms leaves much to interpretation and assumption, however, since the benefits are all futures.
As state and federal programs evolve, it may make sense to commit early to take advantage of a good subsidy program now since electric prices may rise while incentives decline. On the other hand, a new technology breakthrough might mean a decision delay makes more sense.

Geographic Service availability
Solar Site surveys are currently being performed in middle Tennessee area and northern Mississippi & Alabama.

Considerations for Solar Panel System Sizing

The basic questions that need to be answered to determine the size of a solar collection system are:

How much heat or electric energy is needed?
What type of collector will be used?
How much energy will be lost between the collector and the point of use?
How much of the sun's energy that could potentially reach your collector surface actually will? A percentage of the sun's radiation can be blocked by trees, buildings, hills, clouds, dust, water vapor in the air, and other things.
How does the slope and orientation of the collector affect the amount of solar energy received?

Specific Aspects of PV System Siting and Sizing

Photovoltaic panels are affected by partial shade more than other types of collectors. Shade over a portion of the panel can greatly limit power output. Partial shade from towers, poles, deciduous trees and other objects would be considered nearly the same as total shade for older panels. PV manufacturers are gradually reducing this problem. Several locations should be evaluated to find the one with the greatest collection potential. Output will also be affected by the use of trackers, or the number of fixed panel adjustments made during the year.

Siting Domestic Hot Water Collectors

The most ideal water heat collector orientation will typically favor the winter months slightly, to make up for shorter days and the cooling effect of colder temperatures. The panel tilt might equal the latitude plus five to ten degrees. Although partial shading isn't as critical with thermal collectors as with PV panels, we still need to compensate for a high percentage of morning or afternoon shade. To do this, we need to aim the panels more to the west or east, and possibly increase the tilt.

Estimating Rooftop Collector Shading on the Future Home

Solar site analysis is difficult when trying to estimate how much sunlight will strike the walls or roof of a building that hasn't been put up yet. Usually the future rooftop will likely be less shaded than the building site at the ground level. Rooftop shading can sometimes be estimated by taking two readings, one at ground level, and another one ten feet up a stepladder. Any shift in the skyline between the two readings can be used to estimate the correct rooftop solar reception by using proportions. For example, shading reduced by half at the 10-foot level would be approximately halved again at 20 feet. A third reading could be taken from the roof of a nearby building (if one exists) to help get a better perspective on shading patterns in the area. As long as there were not significant potential shade makers to the east and west, we also could go north of the site, to a point at instrument level that is on a line of sight with the future elevated collector.

Basic Landscaping/Organic Gardening

What gardener wouldn't like to know exactly how many hours of sunlight a certain plant is getting (if any)? Or what days of the year does the sun actually reach a specific plant? How about whether a bush planted in October in the shade will be in direct sunlight in March? Ever need to know how much tree needs cropped to insure sunlight on a critical spot? The Solar Pathfinder can do all that and more.

Greenhouse Location

Eventually every gardener considers the purchase of a greenhouse. A greenhouse offers the opportunity to enjoy gardening every month of the year. It also represents a considerable commitment in money, time, and space. Choosing the right site for your greenhouse will not only determine how well it works as a greenhouse, but how much you will enjoy it. One of the most important factors to consider in choosing your site is the availability of sunlight. If the greenhouse is going to be used primarily for starting seeds and transplants or plant propagation in the summer, place it in partial shade to minimize heat buildup. Deciduous trees may be helpful as they lose their leaves allowing solar gain in the winter while still providing shade in the summer (The problem with overhanging trees is one of falling branches that can damage your greenhouse). You can also use a shade cloth to control the amount of sunlight reaching the interior if a partially shaded site is not available. If the greenhouse will be used for growing in late fall and winter, or growing plants to maturity, it will need maximum exposure to the sun. It should receive a minimum of 6 hours of direct sunlight everyday. It is best to position the greenhouse with the ends facing east and west. This will provide more heat gain from the sun during the winter and create less shadowing in the greenhouse. If you have to choose between morning sun and afternoon sun, the plants prefer the morning sun to get them off to an early start. If the southern exposure is restricted, but open to the east, southeast, southwest, or west, turn the greenhouse to the winter sun. Remember the difference in sun angles from summer to winter (the sun is much lower in the winter).

The Solar Site Survey A solar site survey is used to answer several questions for a potential buyer of solar electric equipment:

1) is solar electric feasible for the particular property, and, if so, 2) where should the equipment be optimally placed, and 3) how much equipment can be accommodated

Geographic Service availability Solar Site surveys are currently being performed in middle Tennessee area and northern Mississippi & Alabama.