SOLAR: Will solar save you $$’s? We review the best/worst solar calculators!

September 21, 2008

UPDATED:  9/21/08

“Payback on solar isn’t the most important thing…it is the only thing the vast majority of potential solar homeowners care about.”  

GetWithGreen took a look at how easy it is for us consumers to actually estimate the cost of installation/installing solar during a home remodel – using a web-based solar calculator.  

Below are we have listed a number of sources for solar installation calculators, and we have compiled the most comprehensive list of these calculators available on the web.  We want to warn you, many of these solar calculators appear to made by scientists for, well we couldn’t always figure out who the target audience was :-). 

To help you, we have given a GetWithGreen Rating (“GWG Rating”) to each solar calculator, where 1 is very hard to use, and 10 is the easiest to use – for an average consumer.  You should also know that MANY of the solar calculators on the web are from the same creators, and are just re-skinned (web terminology for different colors).

Before you begin, make sure you have a copy of your utility bill handy because you will need to input either your annual electric costs and/or your monthly electric usage in Kwh into the solar calculator!

my solar estimator find solar

Find Solar ( GWG Rating:  9 )
The “My Solar Estimator” solar calculator tool starts out simple with entry of a zip code and selection of your utility provider and remains easy to use from there on out.  We like the navigation of this solar calculator and believe this solar calculator was designed for consumers like the community.  This solar calculator is used by a number of different websites, and is referred to quite often.


BP solar electricity calculator

BP Solar ( GWG Rating:  7 )
Calculate the potential cost and savings by using a BP Solar Home Solution solar calculator.  Easy to use and very fast calculator.  This solar calculator will estimate out the savings per month off your present bill, and you can adjust the size of the system to determine further savings.  Very easy to use, very friendly.  We think this is a good solar calculator to get your feet wet with before proceeding to the My Solar Estimator tool from Find Solar above.


solar calculator 10



Southern California Solar Calculator (Southern Cal Edison & San Diego Gas Electric) ( GWG Rating: 7 )
Heritage Solar offers a solar calculator that is easy to use and provides savings information for “small”, “medium” and “large” installation scenarios.  






SunPower Solar Calculator (GWG Rating: 7)

This is a very complete and comprehensive solar calculator.  This calculator is almost identical o the Sharp and Kyocera calculators below.  It is built by Clean Power Research.  You definitely have to know your stuff to answer all the questions, and to get an answer.  The nice thing about this solar calculator is that it compares your costs to actually leasing a system through SunPower.   



sharp solar calculator

Sharp USA ( GWG Rating: 6 )
Estimate system cost, monthly savings, and payback using this solar calculator.  This is the same solar calculator as Kyocea, but implemented a bit nicer.  Still requires you to know the cost per Watt to get a good estimation.  



solar power kyocera

Kyocera Clean Power Estimator ( GWG Rating:  5 )
Estimate the energy output, pollution prevention and cost of your grid-connected photovoltaic system using this solar calculator. 

Select the residential option, and input your Zip Code to get started.  Does incorporate tax benefits.  This calculator is used by a number of websites, and can be easily identified by the “cleanpower” text in a webpage URL.  We didn’t find this solar calculator particularily useful for the average consumer because it required you to put in what you think the size of your PV System should be (e.g. 4,000 Watts) and a cost per Watt (e.g. $8 per Watt dc). We question whether the average consumer trying to make a solar decision knows this?


Arizona (Phoenix) Residents ( GWG Rating: 5)
SRP delivers a Solar CostCalc for Phoenix residents.  It estimates the cost of a system and cost savings of the system, but you have to estimate the size of the system.   So you might want to start with the My Solar Estimator, and come back after you’ve done some estimating.


Long Island Residents ( GWG Rating: 5 )
Take a look at what Renewable Energy Long Island (RELI) has to offer. 


pvwatts solar calculator   

PV Watts ( GWG Rating: 4  )
Calculates electrical energy produced by a grid-connected photovoltaic system.  Created by researchers at the National Renewable Energy Laboratory to enable experts to obtain performance estimates for grid-connected PV systems with the US.  This solar calculator, while getting many referrals on the web, appears to be made by rocket scientists for rocket scientists.  It is very difficult to use for the average consumer, but there are instructions that can teach you the science behind the solar calculations. ( GWG Rating:  4 )
Online solar retailer with an easy to use solar calculator that quickly tells you how much solar energy your system will need to output to fullfill you needs.  You can take this system sizing, and then use it on the Kyocera Clean Power Estimator or the PV Watts calculator above.   So, as you can see this is not a complete solar calculator, but a piece of the puzzle.


Texas State Energy Conservation Office ( GWG Rating: 2 )
Basic solar calculator that estimates a system cost, but does not account for any incentives like almost all the other calculators.

So in summary, GetWithGreen believes the calculators we have Rated higher than 5 or higher, can offer you some guidance in your solar education and decision. 

Clearly there is a lot that solar resellers have to offer in the way of estimations, and it’s likely they keep detailed tools close to their chest.  We believe there is a market out there for one of you readers to create a free comprehesive tool.  If it existed we suspect it could demystify solar to the average residential homeowner, and possibly accelerate adoption!

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