Wind and sun oriented are controlling a perfect energy transformation. This is what you need to think about renewables and how you can help have an effect at home.
Solar Energy
Solar Energy
Sun powered, or photovoltaic (PV), cells are produced using silicon or different materials that change daylight straightforwardly into power. Disseminated galaxies create power locally for homes and organizations, either through roof boards or local area projects that power whole areas. Sun based ranches can produce power for a large number of homes, utilizing mirrors to think daylight across sections of land of sunlight based cells. Drifting sun based homesteads or "floatovoltaics" can be a successful utilization of wastewater offices and waterways that aren't naturally touchy. Sunlight based supplies somewhat more than 1% of U.S. power age. However, almost 33% of all new creating limit came from sun powered in 2017, second just to petroleum gas. Sun oriented energy frameworks don't create air toxins or ozone depleting substances, and as long as they are dependably sited, most sunlight based boards have not many natural effects past the assembling interaction.
Wind Energy
Wind Energy
We've made considerable progress from older style wind plants. Today, turbines as tall as high rises with turbines almost as wide in measurement prepare for action all throughout the planet. Wind energy turns a turbine's sharp edges, which takes care of an electric generator and produces power. Wind, which represents somewhat more than 6% of U.S. age, has become the least expensive fuel source in numerous pieces of the country. Top breeze power states incorporate California, Texas, Oklahoma, Kansas, and Iowa, however turbines can be put anyplace with high wind rates like ridges and open fields or even seaward in untamed water.
Hydroelectric Power
Hydroelectric Power
Hydropower is the biggest sustainable power hotspot for power in the United States, however wind energy is before long expected to assume control over the lead. Hydropower depends on water commonly quick water in an enormous waterway or quickly diving water from a high point and converts the power of that water into power by turning a generator's turbine sharp edges. Broadly and globally, huge hydroelectric plants or super dams are frequently viewed as nonrenewable energy. Uber dams redirect and decrease common streams, confining access for creature and human populaces that depend on waterways. Little hydroelectric plants (an introduced limit underneath around 40 megawatts), painstakingly oversaw, don't will in general reason as much natural harm, as they redirect just a negligible portion of stream.
Biomass Energy
Biomass Energy
Biomass is natural material that comes from plants and creatures, and incorporates crops, squander wood, and trees. At the point when biomass is singed, the compound energy is delivered as warmth and can create power with a steam turbine. Biomass is frequently erroneously portrayed as a spotless, inexhaustible fuel and a greener choice to coal and other non-renewable energy sources for creating power. In any case, late science shows that numerous types of biomass particularly from backwoods produce higher fossil fuel byproducts than petroleum derivatives. There are additionally unfortunate results for biodiversity. All things considered, a few types of biomass energy could fill in as a low-carbon alternative under the right conditions. For instance, sawdust and chips from sawmills that would some way or another rapidly deteriorate and discharge carbon can be a low-carbon fuel source.
Geothermal Energy
Geothermal Energy
In the event that you've at any point loose in an underground aquifer, you've utilized geothermal energy. The world's center is probably just about as warm as the sun's surface, because of the sluggish rot of radioactive particles in rocks at the focal point of the planet. Penetrating profound wells carries hot underground water to the surface as an aqueous asset, which is then siphoned through a turbine to make power. Geothermal plants commonly have low emanations on the off chance that they siphon the steam and water they use once more into the supply. There are approaches to make geothermal plants where there are not underground supplies, but rather there are worries that they may build the danger of a seismic tremor in regions previously viewed as topographical problem areas.
Atomic force, the utilization of supported atomic parting to create warmth and power, contributes almost 20% of the power produced in America. The United States has utilized atomic force for over 60 years to create solid, low-carbon energy and to help public protection exercises. The Energy Department's Office of Nuclear Energy's essential mission is to progress atomic force as an asset fit for making significant commitments in gathering our country's energy supply, ecological, and energy security needs. By zeroing in on the improvement of cutting edge atomic advances, NE upholds the Administration's objectives of giving homegrown wellsprings of secure energy, lessening ozone depleting substances, and upgrading public safety. Atomic force stays a significant piece of our country's energy portfolio, as we endeavor to diminish fossil fuel byproducts and address the danger of worldwide environmental change.
Biomass is a natural environmentally friendly power source that incorporates materials like farming and timberland buildups, energy yields, and green growth. Researchers and architects at the Energy Department and National Laboratories are discovering new, more productive approaches to change over biomass into biofuels that can replace ordinary fills like gas, diesel, and fly fuel. Bioenergy can help guarantee a monetarily strong and secure future while decreasing natural effects through: 1.Developing moderate homegrown fills and co-items 2. Propelling clean fuel sources 3.Generating homegrown responsibilities to help the development of the U.S. bioeconomy. Innovative work to change inexhaustible carbon and waste assets into feedstocks for transformation to biofuels, bioproducts, and bio power will reasonably grow biomass asset potential in the United States.
Hydrogen and Fuel Cells
Hydrogen and Fuel Cells
The Hydrogen and Fuel Cell Technologies Office (HFTO) centers around exploration, advancement, and exhibit of hydrogen and power module advances across various areas empowering development, a solid homegrown economy, and a perfect, evenhanded energy future. Hydrogen is the least difficult and most bountiful component known to man. It is found inside water, petroleum derivatives, and all living matter, yet it seldom exists as a gas on Earth—it should be isolated from different components. There are different homegrown assets that can be utilized to deliver hydrogen, including renewables (wind, sun oriented, hydropower, biomass, and geothermal energy), atomic force, and petroleum products (like flammable gas and coal – with carbon catch and sequestration). The U.S. at present creates in excess of 10 million metric huge loads of hydrogen each year, around one-seventh of the worldwide inventory.

Comparing quotes: why are installers proposing different system sizes?

Reading Time: 7 minutes So you have a few quotes, sit down to evaluate them, and notice something right off the bat: installer A and installer B have proposed different sizes for your solar panel system. Why is this? And how can you truly compare apples-to-apples in this scenario? In this article, we’ll review why this might happen – […]

Reading Time: 7 minutes So you have a few quotes, sit down to evaluate them, and notice something right off the bat: installer A and installer B have proposed different sizes for your solar panel system. Why is this? And how can you truly compare apples-to-apples in this scenario? In this article, we’ll review why this might happen – […]Reading Time: 7 minutes

So you have a few quotes, sit down to evaluate them, and notice something right off the bat: installer A and installer B have proposed different sizes for your solar panel system. Why is this? And how can you truly compare apples-to-apples in this scenario?

In this article, we’ll review why this might happen – and what you can do about it!

Find out what solar panels cost in your area in 2021

Key takeaways

  • Variances in system layout, equipment, electricity usage assumptions, and more can lead to different recommendations for system size
  • Communicating and providing additional details to installers can help ensure your quotes are as accurate as possible
  • Register on the EnergySage Marketplace to get custom quotes from local solar installers

A quick review of the solar panel system design process

Before diving into why installers quote different system sizes, it’s important to understand how installers come up with these numbers in the first place.

There are the three primary factors that drive solar panel system designs:

  • How much electricity you use in a year
  • Solar insolation (i.e. the amount of solar radiation that will hit your solar panels)
  • The amount of space available for installing panels

#1. How much electricity you use in a year

First, your annual electricity consumption: installers often look at past electricity bills to determine how many kilowatt-hours (kWh) you use over the course of a year. This number is important, because installers will generally design and recommend a system that will meet as close to 100 percent of your electricity needs as possible (the “as close to” bit is important here, but more on that later).

#2. Solar insolation 

Installers can’t use electricity usage information alone to determine your ideal system size; they need to match up your electricity consumption to the solar insolation at your property to figure out how many watts of solar power you’ll need to meet your annual needs. 

To understand the importance of solar insolation, consider an average 8 kilowatt (kW) solar panel system: this size system will generate noticeably different amounts of electricity in Hawaii (~11,200 kWh per year) than in Vermont (~9,700 kWh per year), since Hawaii is closer to the equator and experiences more sun hours throughout the year. But even two 8 kW systems in Vermont located in the same neighborhood can–and likely will–produce varying amounts of electricity if there are site or system design conditions that hinder access to sunlight (e.g. shade, tilt of the panels, direction the panels face.) 

Installers employ software design tools and satellite imagery to figure out this part of the puzzle – it’s the reason most solar companies ask for your address before providing any sort of numbers! 

#3. Amount of available space for panels

Lastly, available space: unfortunately, not everyone has enough roof or land space to fit all the panels they’d need to cover their electricity needs. In scenarios like this, installers typically look to offset as much of your electric bill as possible, and maximize production with high efficiency equipment. 

We’ve only brushed the surface of design considerations for solar panel systems here; however, we do have additional resources if you want to read more about determining how many solar panels you need, factors that make a home more or less suitable for solar panels, or how installers calculate production estimates.

Questions to ask when comparing quotes with different system sizes

Comparing two or multiple quotes with varying system sizes is never ideal – it can be hard to figure out what’s causing the differences, or which system size is right for you.

Below are a few questions that can help you sort this out:

Are the installers using the same assumptions for annual electricity usage?

We know that electricity usage plays a critical role in system size recommendations, so first ask yourself: are the installers providing quotes using the same numbers here?

When you receive quotes on EnergySage, all the installers will have access to the same bill details. However, if you’re gathering quotes outside of our Marketplace, installers may be using different assumptions for your annual electricity usage.

Keep in mind that it’s very common for installers to update quotes throughout your shopping experience based on additional information or details they gather. Even if all the companies have access to the same electric bill info, one might suggest a larger system if you tell them that you expect your electricity usage to increase in the near future because of an EV purchase or other home electrification upgrades. It works the other way as well; if you’ve talked to an installer about energy efficiency upgrades and expect a decline in your usage, they may recommend a smaller system.

Does the placement of your panels vary between system designs?

Did the installers include system design images in their quotes? If so, compare one design to the next, and in particular, the placement of the solar panels. The tilt of solar panels and the direction they face both impact how much sunlight hits them, and consequently how much electricity they will generate. Generally, most installers will recommend the same planes of your roof for panel placements, but slight variations in design could mean you need more or fewer panels to hit your electricity production target.

What panels did each company quote?

Calculating the size of a solar panel system is easier than you’d think: you simply have to multiply the number of panels by the wattage of each panel. For 20, 320-watt panels, you’d be looking at a 6.4 kW system:

20 panels * 320 watts (W) = 6400 W / 1,000 = 6.4 kW

So, you may be dealing with two companies that recommend the same number of panels, but quoted different system sizes because the proposed panels have different wattages:

20 panels * 320 W = 6.4 kW

20 panels * 340 W = 6.8 kW

Many installers will include details about the proposed equipment in their quotes, but if you aren’t seeing it, ask! Solar equipment is one of the most important factors to consider when finding the right solar solution for you, and you want to make sure you’re paying a fair price for the equipment being installed.

Are local policies influencing system size recommendations?

Like we mentioned above, most solar installers will recommend installing enough solar panels to meet your needs, assuming you have the space available to do so. However, you might find that some installers will recommend a smaller system if there are policies from your utility company or government that restrict system sizes. For example, in some states, systems need to be under a specific size to take advantage of net metering or certain solar incentive programs.

Hopefully, all installers providing quotes will be familiar with your local utility company’s interconnection policies and quote accordingly. However, installers that are new to your market or just breaking into the solar industry may be unaware that such restrictions exist – that’s just one reason why finding a reputable, experienced installation company matters!

Do any of your quotes include a battery?

Batteries are becoming an increasingly popular addition to solar panels, especially as costs continue to decline. If you install a solar-plus-storage system, the battery you choose and how you plan to use it (e.g. for backup power, self consumption, rate arbitrage) plays an important role in sizing your solar panel system. Don’t be surprised if an installer that offers a battery in their quote suggests a slightly larger system than one that doesn’t – you’ll want enough extra electricity to charge your battery, after all!

How do the production estimates compare?

The word “estimate” is key: it’s impossible to determine the exact number of kilowatt-hours a solar panel system will produce in real life conditions since no one can predict the weather. 

Because installers use different tools to generate system designs and production estimates, slight variations in both are bound to happen. Additionally, some installers are more inclined to provide generous production estimates, while others choose to stick to more conservative numbers. Of course, more conservative estimates can lead to larger system size recommendations, while installers being more ambitious with their production estimates will generally recommend smaller system sizes.

The best way to compare production estimates in relation to system size is to calculate the system’s production ratio

Production ratio = year 1 production estimate / system size (Watts)

By comparing these ratios across your quotes, you can get a feel for what’s normal for your property, whether your potential installer is being more or less aggressive with their production estimate, and how that could be impacting the system sizes in your quotes.

You can find more information about production ratios and how to evaluate them in this article.

Next steps: finding the right system size for you

Whether you’ve figured out why the installers quoted different system sizes or not, there are a few steps you can take to make sure your quotes are as accurate as possible:

  • Provide the most up-to-date electric bill information, with any additional context: above all, make sure that all the installers providing quotes have access to accurate electric bill information. And, if you plan to increase or decrease your electricity consumption in the future, make sure the installers know this, along with the reason why because it will influence their system size recommendation.
  • Ask installers to update quotes according to your preferences: remember, your initial solar quote is not set in stone! Companies can adjust their proposals as you get a better idea of what you want. So, whether you fall in love with a particular solar panel or simply decide you don’t want solar panels on one portion of your roof, let the installers know so they can make sure their quotes reflect these preferences.
  • Invite installers out to a site visit: site visits are a great opportunity to meet a prospective solar installer and ask them questions – they’re also the perfect time for an installer to take measurements and fine-tune their system design. Fortunately, most solar companies offer free site consultations for prospective customers.

Try not to worry too much about slight variations in system sizes between quotes – we know… easier said than done! But at the end of the day, it’s most important that you find a solar company with a proven track record of designing and installing high-quality systems for a fair price. Whether you land on a 6.6 kW system or a 6.8 kW system, you’ll still save money on electric bills!

Compare and review quotes on EnergySage

On the EnergySage Marketplace, you can receive up to seven quotes from local solar companies. These quotes will include details about proposed system sizes and equipment, and use the same standard assumptions, making it the most transparent and easy way to compare. If you’d like to start with some ballpark numbers on estimated solar costs and savings, try our Solar Calculator. 

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