|Once you have determined the type of renewable energy system you would like to install whether it be
photovoltaics or a solar hot water system, the next major step is to choose the installation location!
|First and foremost in installing a renewable energy system is cost and payback!
-To reduce the installion cost, materials, labor and system size must be kept to a minimum while
still achieving your energy requirement goals.
-To increase payback, maximum gain, minimal losses and maximum efficiency must be achieved.
| So how should I install my new system?
If you are looking to get the most gain from your system, the things you should consider are:
- Install the system so it can be adjusted to the sun angle throughout the year.
- Install the system in an area that gets the most overall and direct sun each day and throughout the year.
- Install the system such that it can take advantage of diffuse and reflected radiation.
- Install the system so that it is sheltered from the harsh elements that can hinder performance such as
wind, cold, ice, snow and heat as well as trees that could cause shade and physical damage from lost
- Determine the location of components such as batteries and inverter or hot water and heating systems,
reduce wire and piping arrangements and locate the panels as near as possible to reduce losses.
- Allow for easy access to components for maintenence to keep systems running correctly.
| Where then can I install my system if the roof is not the best spot?
-On the ground, leaning against or attached to a rail or fence, or on an adjustable, movable or fixed rack
or without reflective ground cover.
-On an outbuilding or specially designed shed, that may or may not house the rest of the system's
-On a sunny patio, deck, outdoor space or pool area installed as a privacy screen or overhead shading.
-On the side of a building, accessible from inside or out, to adjust angles or to provide shading overhangs
in summer months or else fully intergrated into the sidewalls or roof.
-On a natural earth berm or hill that will keep the panels cool in summer and sheltered in winter.
-Any spot that gets the most overall sun each day all year and allows for easy, safe and total access for
maintenence and repair throughout the year and the life of the system.
|With catchy names like "The Million Solar Roofs Project" many consumers assume, or are led to
believe, that solar needs to be installed on a roof!
This may work well in moderate climates but it can hinder performance in hotter and colder climates. Most
consumers do not consider a ground installation, but when you look at all the large MegaWatt Photovoltaic
and Solar Steam energy plants, the system's panels are arranged in a large open area, designed to maximize
gain over the entire day by either physical arrangement or tracking devices. Distances between panels, and
pitch, allow for maximum gain with no shading, while the panels themselves create their own shade to keep
the area behind them cool and operate more efficiently. Maintenence also becomes easy with plenty of safe
space to work.
Installation costs can increase due to working conditions and proper securing of the panels on a roof.
Grounding issues for PV installed on roofs can also add greatly to the installation cost. Also, most insurance
companies do not cover solar components or damage from such components to a roof.
|So before you install your dream solar machine, do as the ancients have done,
observe your surroundings and the path of our sun and the stars to align your system.
If ancient people can align great pyramids,temples and homes to gain energy, so too
can you to gain yours!
|Keep Installing Solar Simple !
| If I must install on a roof, how should that be done?
If you live in the norther hemisphere, and have a roof that faces south, and it has a pitch with a value
near your latitude, eg. your roof has a 12 pitch or a 45 degree slope and you live at a latitude of 45
degrees north of the equator, then you could mount them directly on the roof, as long as you leave an
airspace between the roof and the panel to allow for cooling circulation and water runoff. If your roof
has a pitch different from your latitude then the panels should be attached to a rack that puts the panels
at the correct angle. When installing, the removal or non-removal of the panels should be taken into
consideration should the roof ever need to be replaced.
Since the panels are fixed, their angle cannot be changed over the seasons to get as much direct gain,
or sun coming in perpendicular to the panel, as possible, thoughout the year. If installed in areas that get
snow, build up of snow and ice on and around the panels can greatly reduce the gain and possibly do
damage to the panels. Installations on roofs in hotter climates, or even during summer months
elsewhere, also greatly reduce energy gain by increasing energy losses in the form of heat and lowering
efficiency, just as with any other machine or animal when they get too hot.
Photovoltaic's efficiencies drops dramatically when they get overheated and methods are investigated to
keep them cool during these times. This is why they work well in outer space. Even hot water panels
can drop in efficiency, even though you would think that you would get hotter water if the whole panel is
hot. As a hot water panel begins to absorb heat through it's absorber plate, some of the heat is
transferred to the water and some of the heat raises the temperature of the air space within the panel.
Some of this air transfers it's heat to the working fluid and some of it is lost to the surroundings, passing
through the framing, glazing and insulation. As the air in the panel and even the framing gets hotter, and
the temperatures rise up above the surrounding temperature, the rate of heat loss increases and the heat
finds it easier to move into the surroundings instead of into the fluid, thus the amount of incoming
radiation that gets transferred to the fluid reduces and in turn reduces the efficiency of the panel.
This is why a differential controller is used with solar hot water systems to ensure that any water coming
from the panels is hotter than the water in the storage tank, other wise heat could be taken from the tank
and lost into the panel and out to the surroundings. Modern charge controllers now incorporate
temperature compensation for PV.