Why You Shouldn’t Use Google’s Solar Panel Calculator as A Solar Quote

Cost Of Solar Panels
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What Google's solar panel calculator actually does

Although a great idea, Google’s solar panel calculator is not a perfect guide for solar power. The impact residential solar can have on a home takes more than an impressive looking display to find.

Formulas and data specific to the state and utility in the area play a pivotal role in a quality solar calculator. However, this information on its own is not enough to give an accurate quote.

The variables that come with each installation make solar calculators best used as a starting point, not as a solar quote. Understanding how Google’s Project Sunroof works will help interested parties understand why this is the case.

How Google’s Solar Panel Calculator Works

Google’s Project Sunroof launched in 2015. This program is a tool that allows people to see how affordable solar can be. It is accessible via the search engine results pages. 

One of the reasons why this solar calculator is so successful at promoting solar panel installations is its user-friendly visual aids. These visual aids allow interested homeowners to see the potential savings of solar for their homes.

There are many features about this solar calculator that make it appealing. Some of these include Google’s home images, roof shading technology and solar investment savings calculations.

Google’s Aerial Solar Roof Imagery

Google solar roof imagery technology from Google Maps is a base for its Solar calculator, allowing the calculator to tailor to individual homes. This program, paired with solar shading technology, gives homeowners an idea of what solar could save them.

Google’s Solar Shading Tech

Google’s project sunroof shading technology allows people to see if their home is a good fit for solar. If the sun exposure on the roof is limited, the solar panels won’t produce as much power.

This program shows people the sun exposure on their roof. It also gives estimated hours of sunlight throughout the year and usable roof space.

Google uses a color gradient to represent areas of the home with higher sun exposure. Purple areas have shading, while yellow areas have greater sun exposure. Homeowners with minimal shading would be wise to investigate solar.

Savings Estimates of Google’s Solar Calculator

Google’s solar cost calculation covers each of the three most common methods of payment for solar. These financing options include cash, lease and loan.

Default Settings and Assumptions in the Savings Estimate

Although it can be adjusted, the solar calculator’s default setting assumes an average monthly utility bill. It then estimates available space to determine the max amount of energy offset a solar array could provide.

Each of these financing options takes into account incentives for the area and the up-front cost of the array. The purchasing option gives an estimated payback period, 20-year benefits, and 20-year savings.

The lease and loan both have the same assumed rate and term of 20 years. They also have an estimated yearly and 20-year cost. These google solar calculations are all based on a 2.2 percent yearly-rate increases for the utility company in the area.

Possible Issues With This Solar Panel Calculator

As stated above, solar calculators are great for those that have a piqued interest in solar for their home. If, however, the customer wants to know for sure that solar is a viable option for them, they need to talk to a solar professional.

Solar calculators don’t account for all the factors necessary to give an accurate solar quote. Most solar calculators do not account for the customer’s monthly energy usage and exact roof measurements.

Another issue is that some of the tools provided in solar calculators aren’t representative of every situation. If solar calculators are considered an accurate estimate instead of a starting point, this could be detrimental to perceived savings and solar potential.

Google Shading Tools Compared to Solar Panel Mapping

Designing a solar panel system requires tools that Google’s calculator doesn’t use. Not taking into account these tools makes Google’s sunroof calculations less accurate than solar company solar calculators such as, Go Solar Group’s Utah solar savings calculator.

Google Shading Technology Limitations

If a roof doesn’t have enough sun exposure, Project Sunroof assumes the home isn’t a good fit for solar. However, this may not be the case. Homes without sufficient un-shaded roof space might have the option to install a ground mount

A Solar Calculator Meant to Educate the Public

When Google first launched Project Sunroof, it informed people about residential solar and why it can be a profitable financial decision for them. Google later decided to use the tool to generate leads for paying solar companies. The Sunroof Project was then switched back to an educational tool in 2017.

Google’s solar calculator is better, now that it has stepped away from lead generation. However, this program still struggles to address all the moving variables that make solar panels a good fit for a home.     

Project Sunroof: A Good Place to Start

Project Sunroof is a great place for interested parties to start their search for solar. This program gives a good idea of whether trees or other objects shade the roof too much.

It, however, does not address every scenario, making it a subpar cost estimator. If a homeowner wants a solar estimate, it is best to acquire a solar quote. Receiving quotes from different solar installers helps the customer determine the best price and product for them.

One of the variables oversimplified in the Google solar calculator is solar financing. Each solar company has different financing options, products and pricing, which makes generating return on investment hard for a general solar savings calculator. 

Google’s Solar Calculator Savings Issues

Using a one-option-fits-all can lead the customer to think that this is the price that they will pay no matter which solar company they choose. However, these estimated prices are not realistic for a company with different pricing and product options than the ones in Google’s savings calculator.

Differences in Solar Financing 

One area where having a resolute setting is a problem is financing. Every loan and lease in Google’s solar calculator has a 20-year term with a set interest rate. However, each solar company has different financing options, which would change the savings.

Product Price Differences 

Another factor that makes a one-answer-fits-all hard is the variance in solar products. Even if two solar homes have the same energy usage, it may not cost the same for the array they chose. The type and brand of solar equipment used as well as the desired amount of offset influence the array price.

Google Solar Calculator and Company Discounts 

Solar company discounts and customer referral programs are also not taken into account in Google’s solar calculator. One discount that many solar companies provide is a cash financing discount. Go Solar Group gives a 10 percent discount for cash purchases.

Cost of Power vs. Power Used

Google and many other solar savings calculators use average electric bills as a gauge for how much solar would cost. The problem is that sizing a solar array with a utility bill is not accurate.

Different Utility Rates

Each utility company has different rates, which makes sizing solar off of the average utility bill a messy process. If one utility charges 10 cents per watt while another charges 12 cents, the monthly bill for the same amount of electricity will be different. 

Utilities That Provide Both Gas and Electricity

Another issue is that some utility companies provide both gas and electricity. If the customer doesn’t know what to look for, they may include both in their bill estimate, which would throw off the savings. 

The Best Way to Calculate Electricity: Usage

The best way to determine how much energy a home uses is with the monthly electric usage of the house over a year. Monthly usage is the amount of electricity used. This measurement is the same regardless of the price the customer paid that month, making it easier for a solar designer to design a system that will cover the energy needs of the home.

Using Google’s Calculator and Solar Quotes

Using Google’s solar savings calculator is not bad. It is a great place to determine if a home has solar potential. However, it doesn’t have all the answers.

We recommend looking at multiple solar companies, so you can better determine which is the best option for your home. If you would like a rough idea of what your solar savings could be with Go Solar Group, we have our own solar savings calculators that take into account the products we offer and the areas we serve. We also create free hand-delivered customized quotes for qualified homeowners.


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