(207) 797-0979

Getting Started with Solar

The first step in adopting solar power is to educate yourself as to your options.  Our links section has many helpful web sites.  We regularly schedule free classes and often we exhibit at home shows.  We are happy to answer questions over the phone or mail/email.

Calculating sizing needs for solar

When we talk with you we will ask questions about your current energy usage to help design a system to meet your unique needs.  Below is some information to help you understand the process.   We usually size systems to your current living situation, not to the number of bedrooms or needs of the next homeowner.  Remember most systems are expandable if you plan ahead.

Solar Domestic Hot water

Government guidelines recommend about 15-20 gallons per day for an average person. We generally provide a tank size to meet about 2 days of needs. With the majority of the evacuated tube systems we sell we figure on 1 tube creating 2 gallons of hot water. So if you had 3 people (3 x 15gl = 45gl) we would suggest an 80 gallon tank and about 40 tubes to cover the 2 days of need.  Standard tank sizes are approximately 60, 80 and 120.   Most solar thermal collectors are about 6 ft tall.  40 tubes would be almost 8 feet wide. 

Solar Thermal Space heating

Space heating is based on the buildings Btu’s needed. No two building are alike. In new construction the Btu load is easy to calculate. For existing homes we can also look at current fuel usage, the rated output of the heating equipment, and do heat loss calculations based on your homes size, window type and sizes, insulation levels and site information.  Our Thermomax output chart is helpful in understanding how many Btu’s a given size system can generate. Every building is unique; call us for assistance.

Electrical usage and Solar

Reviewing your power bill for the past 12 months will give you a good starting point on your electrical usage.  Most people choose a grid tied photovoltaic (PV) system with a net-use meter so they avoid the cost and maintenance associated with batteries.  With a grid tied system you are credited for power created and debited for use over a 12 month window.  It is not necessary to cover the monthly spikes as they average out over the year.  PV systems are expandable as long as you pre-plan.  Of course the more you can reduce you load, the smaller and less expensive your PV system will need to be.  A PV system does not need to offset 100% of use.  If you have 4 PV modules that are each 250 watts the total is 1000 watt or 1 kW (kilowatt).  This 1 kilowatt rating is an instantaneous rating under ideal conditions.  Your electric bill is in kilowatt hours (kWh).  In Maine a 1 kW system will produce about 1,300 kWh annually in a good location.  This is about 110 kWh per month.

Solar Pathfinder

Determine sun and site needs for solar

Some homes are not good candidates for solar thermal hot water or PV electric because of shading issues.  PV likes to face south, solar thermal is more forgiving but cannot face north.  Both need sun, especially from 9:00-3:00.  If you are concerned about a tree or roof lines blocking the sun, a Solar Pathfinder (shown left) can determine the extent of the problem, over all seasons (remember the sun is lower in the sky in the winter and shading issues change).  Solar Panels are about 6 feet tall and 4 feet wide.  For hot water you need 2-3 of these and for PV electric generally about 12 to offset a $60 electric bill.  While this sounds large, remember your roof area is huge.  It is possible to ground mount or vertically hang panels.  Sometimes just topping a tree can solve a shade problem.

Determining wind speed for turbines

If you live on the coast, or high on a hill where you often have winds over 15 mph you may have a good site for a wind turbine. The first step is to go to the government wind study pages, and look at the wind map for your area. To be certain your site has the wind speeds you need a wind study should be done.  You may find your home has consistent wind of 20 mph, or you may find you have low average wind, but lots of gusts over 35 mph. Different turbines meet different needs.  The Tangarie vertical turbine that we sell does an excellent job when turbulence is a problem. Trees, hillsides, and tall objects,  often cause turbulence that can make standard windmills ineffective.

While wind turbines often quote the speed at which the start working, the numbers that matter are the wind rates that actually produce useful outputs.  Generally the kick in speed produces almost no electricity.  Until you reach 20 mph winds you will generate very little electricity

Provided you have a good site, electricity from wind can be about the same cost as photovoltaic panels.

Back up systems & winter

When we install a solar thermal or PV system we know there will be times when it will be covered in snow and that is taken into account when we quote performance.  A backup system is always in place (normally your existing system).  In the case of a hot water system it may simply be an electric element within a water tank or an on-demand tankless water heater.  For a large home with heating and many residents we would install a high efficiency condensing gas boiler. The important point is we know a solar system is not going to generate every single day.  That is why a hot water system has a large storage tank.  Your backup system will seldom come on outside the short days of winter.  For PV and wind you will either need to remain tied to the grid, have a large battery bank, or a generator.

snow and PV on a metal roof at SolarisMany people worry about the impact of winter on their solar system and output.  When we give estimates on the expected output of your system it includes the fact that our winter days are short and we have snow.  Obviously Mother Nature will give us changing weather patterns from year to year and it will impact your systems generation.  

We do not recommend you attempt to remove the snow from your system.  You risk damage that will be much more expensive than the lost power generation.  The systems we sell are designed to withstand our snow loads. As you can see from this picture of our office the snow actually clears from the panels quicker than it does from the metal roof. Solar electric Photovoltaic modules actually perform better in cold weather.  In fact you will find the highest peak production will be on cold clear winter days.  Of course the overall product for any given day will be higher in the summer since the days are much longer.   

Request a solar site evaluation

Once you have done your research on the many types of solar power products, are comfortable with the costs, and have an idea of your goals, it may be time for a site survey. When you give us a call our first step will be to pull up your site using Google Earth to measure the roof and determine orientation.  We will answer all your questions and may be able to give you a estimate over the phone.   We can set up a time to visit your home to evaluate your existing equipment to determine the most cost efficient way to integrate solar.  If shading is an issue we will bring a Solar Pathfinder to help determine the extent of the shade throughout the seasons.  The more information you can provide us, the more accurate the pay back information will be that we provide you.  Ideally we need to know the current volume of fuel used for each application.  Often, there is just one fuel number, and we have to use averages.  If you are considering solar hot water note your fuel reading at the end and start of the next heating season.  This will tell us the amount of oil used for hot water vs. space heating.  A home site survey usually takes 1-2 hours.  Depending on the complexity of your needs, we will have a proposal to you in about a week.  We will include possible efficiency upgrades for your existing systems.

Picking the right solar system and best solar installer, made easy

We always recommend you get a multiple quotes.  Be certain to define your needs consistently.  Make sure you feel comfortable with whoever will be your point of contact,  the skill level of technical people that will be involved in the design & installation, and check references.  Thoroughly research the manufacture of the product.  All of this sounds like quite a task, but we have a suggestion to make it all easy.  Get your quotes and cross off the pricing.  Give each vendor the other companies quote and ask them to find the problems.  Then go back to the original vendor for clarification.  This way you get the insight of industry insiders.  You will quickly find out who really knows their product, their competitor’s advantages and disadvantages, and if anyone is misleading you.

Contract & Payment for your solar system

Often the proposals we send contain a number of different options.  Once you have made a decision we will forward a contract and have you pick your install date. We generally require a 30-50% deposit to reserve your install date.   Normally equipment takes about 2 weeks to arrive. 

We offer a number of no money down finance options with rates as low as 4.99% and the tax advantages of deductible interest payments.  The loans are usually structured so that the loan payments are less than the energy bills would have been so you are cash positive from month 1.  

Installation of your solar system

Your contract will outline the time needed to complete the install.  In new home construction, we set the expected dates for each stage of the job, working closely with your builder.  Fall is our busy season and it is best to book early.  We do installs throughout winter; we just clear the snow from the roof in the area where we need to work.

Usually we need access to the house each day.  It will be necessary to turn off the homes water supply for a few hours while we tie in a new hot water system.  With PV or wind we will need to shut down and tie into the electrical system.

You can be certain that your grounds will be left neat, we will not trample your landscape, and our techs will keep your floors clean and messes picked up.

Before we leave you will be fully trained on the operation and care of your new system, everything will be labeled, and all your operation manuals will be placed in a folder.


Ready to get started?

Contact us today with your questions or to set up your free consultation.

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600 Riverside St.

Portland ME 04103

(207) 797-0979

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