1) Evaluate Your Project

1.1 Determine your current electricity usage

Using your electric bills, find your total electric usage (preferably for at least the last 12 months) in kilowatt hours (kwh). 

If you are an Eversource customer, you can download what you need by creating an account at www.eversource.com and going to View Account > Usage History. A table of Usage (kWh) is provided per month for the last year or more. Sum up the last 12 months to get a number typically between 10,000 and 20,000 kWhr/year. This is the value you will need in later steps. You can average the last 3 years and/or put in monthly values in OpenSolar later so you may want to download the data into a spreadsheet.

Click here for detailed instructions on how to download your use history from Eversource

The data from this download will help determine what size solar system you need. You may choose to target replacing just part of what you use now, all of it, or even more if you anticipate increased usage.

1.2 Quick evaluation of your site for Solar

Before you invest too much time and energy, it is worth doing a quick evaluation of your site (house for rooftop, yard for ground mount). Rooftop systems are generally the most cost effective because you use existing structural support, have shorter wire lengths, and may have less shade because your panels are higher.  If your roof is shaded or complex, a Ground Mount is an option if you have an open area in your yard.  OpenSolar is a great tool to evaluate your roof, shading and ground mount options.  OpenSolar enables you to quickly rough out a design with analysis of the energy you can get (based on orientation, shade, etc.).  OpenSolar will also get you most of what you need to estimate the cost. Create an login in at www.opensolar.com, Before you start a project in OpenSolar, request that we set up a project in HAREI’s OpenSolar account for your project and set-up a project folder on HAREI's Google Drive .   A HAREI member will create project and link you to it.  By linking to a project in HAREI's OpenSolar account you benefit from: some set-up that has been done to streamline process, ability to share your project with experienced HAREI members, and an interface that exports project information into a HAREI tool that aids in electrical design and creates a material list for soliciting quotes.

 If rooftop is the best option, you will also need to evaluate your roof structure (most towns may require a professional engineer’s evaluation).  Details on how to do this are covered in Section 2.1

Click here for detailed steps showing how to set up an account in OpenSolar, link to the HAREI2023 account, and design a solar array for your site.

1.3 How much DIY

To assess the cost (in time, money and your well-being), you need to decide how much of the work you can/will do yourself.  

• We have some members who did it all themselves.

• Others contract some (electrical is common).

• Some contract everything except the installation of the panels which isdone with the HAREI team of volunteers as “Solar Raiser”.

• Still others choose to hire a solar installation company to do it all.  

Click here for a chart which provides cost ranges and helpful information for the typical professional services used by HAREI members.

Note that it highly recommended to attend a couple of Raisers before planning your own as you will learn by doing and there is a lot to learn! HAREI is  a Pay-It-Forward model and it is expected that if we hold a raiser at your site, that you will volunteer at several other Raisers.

1.4 Financial considerations

You may have already done a quick financial assessment of solar or you may be driven by reducing CO2.  

The results of the preceding steps get you most of what you need to do a financial justification.    

• The work you completed earlier with  OpenSolar (step 1.2 above) provided a rough estimate of HAREI cost assuming use of a Professional Engineer to check your roof structure, a contractor to install and roughly align roof mounting feet and rails, and a NH-licensed electrician to do the AC portion of your installation.

• The chart you accessed in the DIY discussion (step 1.3 above) suggests adjustments to the costs if you are qualified to safely do some of this work yourself.

You may also need to consider financing.  Go here for financial justification of your solar project.

Having determined the goals and parameters for your system, you can go on to turn that into a system design.

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