Introduction
Benefits
Equipment & Services
Hiring Contractors

1. Introduction

The energy from the sun can be used to generate electricity in our homes. That possibility is now within closer economic reach for Colorado homeowners who want an “electric generating station” on their roof or in their yard. As a result of the November 2004 Colorado vote in favor of Amendment 37, there are utilities beginning to offer rebates for solar electric, or photovoltaic (PV) systems.

There are three basic types of solar electricity systems: Stand-alone, or off-grid, systems are installed when there is no available connection to a utility power grid; Grid-connected systems are installed when a utility grid connection is possible, and back-up systems are used if the utility grid is not reliable or has frequent blackouts. Amendment 37 is designed to provide rebates for grid-connected systems, allowing any excess electricity produced by the home to be “sold” back to the utility.

2. Benefits

Electricity Savings
The energy savings depend upon the size and performance of the PV system.  A typical on-grid PV system will provide $200 or $300 worth of electricity per year.  This can be a large portion of the electricity use in a very efficient home, but is just a small portion of the electricity use in an efficient home.  The smart approach is to install energy efficiency measures as the new PV system is being purchased so you can enjoy the savings from efficiency and solar.

Conservation and Renewable Energy
Installing a PV system provides the satisfaction that you are doing your part to use renewable sources of energy, extending our current energy supplies, while reducing carbon emissions and environmental pollution.

Increased Home Value
Because there are so few grid-connected PV homes in Colorado, studies have not been conducted to see whether a PV home’s value is higher than a comparable home without the PV. However, it seems that home buyer would pay more for a home that reduces their electric bill by about half--especially with the prospect of increasing electric utility bills.

3. Equipment & Services

For solar electricity you need a solar panel that consists of one or more solar cells. When sunlight falls onto a solar cell, the solar cell material absorbs some of the light particles (so called photons). Each photon contains a small amount of energy. When a photon is absorbed it starts a process of freeing an electron in the material of the solar cell. Because both sides of a solar cell are electrically connected with a wire, a current will flow when the photon is absorbed. The solar cell now produces electricity, which can be used instantly or stored in a battery. A PV home uses only a few pieces of equipment:

• The PV panels represent perhaps 80% of the total costs. The panels often come with a 20 year performance warranty.
• Module mounting systems are used to fasten the panels to your roof.
• Direct grid-tie inverters convert the direct current power produced by the PV to alternating current used in the home and sent to the grid through net metering. The inverter represents about 10% of the total cost, and they typically come with a 5 year warranty.
• All the necessary wiring.
• Safety equipment includes a DC Combiner Box for the wiring, a DC Disconnect so the PV can be removed for service or repair without leaving hot wiring exposed, and an AC Disconnect that is required by the utility to protect them from electric current from your PV when they are doing service in your area.

There are a few key criteria to evaluate in determining if your home is suitable for PV:

• Orientation. Your roof or other unshaded area needs to face south.
• Tilt angle. In the winter the sun will not reach the same angle as in summer. Ideally, in the summer solar panels should be placed somewhat more horizontal, to benefit most from the sun high in the sky. However these panels will then not be placed optimally for the winter sun. To achieve the best year round performance solar panels should be installed at a fixed angle, which lies somewhere between the optimum angle for summer and for winter. A solar contractor can help you determine the optimum tilt angle.

4. Hiring Contractors
Download our solar contractor comparison form (Acrobat reader .pdf format). Find photovoltaics installers from the list of our list of solar contractors.

This is a new industry in Colorado, except for some companies who have installed PV in “off-grid” homes. It is important to carefully scrutinize installers before signing on the dotted line. The good news, however, is that a PV installation is essentially “plug and play” with a minimum of maintenance. There are no moving parts to fail, and the solid state equipment comes with long warrantees. 

Questions to ask
Use our checklist of questions to evaluate contractors. However, due to substantial incentives for PV in Germany, Japan, California, New Jersey, and elsewhere, coupled with a worldwide temporary shortage of polysilicon, getting timely delivery of service may be a problem. Ask the contractor when he or she can give you a date for installation, and if their can be a delivery of service guaranty.

Certifications
Ask if they have been certified by Colorado Solar Energy Industry Association (COSEIA). Make sure equipment is certified by Solar Rating and Certification Corporation (SRCC).

References, licensing, insurance
It is always important to speak with previous customers, check with the Better Business Bureau and ask for verification of the necessary licensing and insurance requirements.

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