14 Things You Should Know Before Buying A Solar Power System For Your House

Saving money and doing something positive for the environment: these two reasons drive most homeowners to consider installing solar power. They’ve heard they can save money on their electric bills, and they know increasing the use of clean energy is a positive step for the planet. It’s not always easy to know where to begin. Some of the questions a homeowner might ask include:

1. Does my town/city/utility support the use of solar panels?

2. Is my home located in a good spot for a solar power array?

3. Would I have to fix my roof first?

4. How many solar panels would I need, and how much would an installation cost?

5. After considering the expense of panels and installation, how much money will I really save over time?

6. What type of solar panels would best suit my budget and needs?

The answers aren’t simple, and they vary depending on the location of a home; whether the roof does need a repair before installing solar panels; federal, state and municipal programs and solar power incentives; and the rates and policies of local utilities. That’s why it’s important to contact a qualified, professional solar installer—or even to talk to more than one – to request a site visit, a quote for panels and installation, and a savings forecast with a timeline for those savings.

Finding the Answers to Your Initial Questions

Many potential solar customers first do some research online. You can find information on local, state, and federal solar incentives as well as the average time expected for a solar array to pay for itself in your area. A professional solar installation company will send a sales representative who can explain the local, state, and federal incentives for installing solar panels in your area. In addition, he or she will understand your utility’s policies and will explain how your solar array will provide electricity to the grid, possibly yielding credits from the utility toward your electric bill (unless you are installing an off-grid system with battery storage that will directly power your home). After taking a look at your roof and the positioning of your home related to the sun and shaded areas, examining a recent utility bill to determine your average monthly power usage, and asking you what percentage of your bill you would like to offset with solar power, the installer will estimate the number of panels you will need. Often the installation company will send a professional roofer to determine if a roof repair would first be needed, and will take some time to design an array that would meet your needs before providing you with a final quote. Once you receive the quote and learn how much your electricity bill will go down on an average monthly basis, you can factor in tax and other incentives to estimate how long it will take your array to pay for itself before you start experiencing significant savings.

7. What Factors Affect the Number of Panels You’ll Need?

The question of how many panels you will need will be determined by your installer depending on a number of factors:

8. What percentage of your electric bill do you hope to offset with solar energy?

9. How much electricity do you use in an average month? (Consider potential future needs, such as electric car charging)

10. How much sun does your area receive?

The National Renewable Energy Laboratory provides a handy map that tells how many kWh (Kilowatt hours) you can generate in one year from 1 kW of solar panels if they are situated in an ideal spot in your area. Find their maps here: https://www.nrel.gov/gis/solar.html. Your installer will adjust for expected losses from heat, wiring, etc.

11. Does your state/utility offer Net Metering (credit on your electric bill based on the amount of electricity your panels feed into the grid)?

12. Will your installation include battery storage?

13. What is the maximum power output and efficiency of the solar panels you will install?

14. How many panels you need will depend largely on two main factors: power and production.

Solar Panel Efficiency Explained

When consumers evaluate solar panels, they often focus on the advertised maximum power (Pmax). This measurement represents a solar panel’s theoretical power production under ideal sunlight and temperature conditions.1 Think of it as the maximum amount of electricity a user can expect a solar panel to produce in an ideal solar environment. In truth, a solar environment is never ideal every day. Regional differences, as well as seasonal and weather changes, limit the value of the Pmax measurement when trying to determine the expected long-term performance of a newly installed solar array. It is important to consider the efficiency of a solar panel.

Solar Panel efficiency can be defined as the “Ratio of Solar Panel Power and Size (W/m2 ); at Standard Testing Condition” (STC). Universally, STC is measured as 1,000W/m2 of sunlight, temperature of 25 deg C, and air mass of 1.5.

High Efficiency LG NeON® 2

Below is an example of efficiency calculations for 60 cell and 72 cell:

LG NeON® 2 panels: NeON® 2 60 Cell: STC Power Rating- 340W/0.34kW;

Length – 1.686m; Width – 1.016m

• 0.34kW / (1.686*1.016)m2 = 0.34 / 1.7129m2 = 19.8% Efficient

• Panel Power (in kW) = 0.34

• Length (in meters) = 1.686

• Width (in meters) = 1.016

NeON® 2 72 Cell: STC Power Rating- 405W/0.405kW; Length – 2.024m; Width – 1.024m

• 0.405kW / (2.024*1.024)m2 = 0.34 / 2.0725m2 = 19.5% Efficient

• Panel Power (in kW) = 0.405

• Length (in meters) = 2.024

• Width (in meters) = 1.024

LG NEONR

Armed with the knowledge of a panel’s efficiency rating, consumers can determine reasonable expectations of the performance of their installed solar systems in different sunlight conditions. Utilities and homeowners who want to maximize the amount of electricity generated by their solar systems should always choose high efficiency panels. High efficiency panels purchased at a good price represent the best value for solar customers. The added efficiency means fewer panels are required to generate the same amount of energy.

Energy Efficiency Estimated

LG Solar and High Efficiency Panels

The efficiency rating of a solar panel varies by manufacturer and panel type. LG Solar’s goal is to manufacture high efficiency panels that will provide LG customers with a solid return on their investment.

What this means is that LG Solar’s panels produce more watts of electricity per watt of sunlight than solar panels with lower efficiency rates (most conventional panels on the market today). LG Solar is constantly innovating new technologies that boost our solar products’ output and efficiency.

LG NeON® 2 BiFacial Panels and Double-sided Generation

LG Solar’s 72 cell BiFacial solar panels are a commercial product designed to absorb irradiance from both the front and back sides of the cells thanks to a transparent back sheet. The dual faces of the cell allow for higher energy generation. The increased kWh/kW leads to a faster payback time and return on your investment.

The reactiveness of the surface on which the panels are installed can help boost output and efficiency.

NEON2-BIFACIAL

The NeON® 2 and Cello Technology™

The NeON® 2 is LG Solar’s best-selling solar panel, thanks to its high efficiency rating along with high power output, outstanding durability, and aesthetically pleasing design. But how is its efficiency rating achieved?

LG Solar’s NeON® 2 panels incorporate a technology called Cello (Cell connection with Electrically Low loss, Low stress and Optical absorption enhancement) Technology™. Cello Technology uses 12 circular wires in each cell instead of the usual busbars. The circular wires scatter light effectively, improving light absorption. Then, the 12 wires reduce the loss of electricity because of the increased number of pathways available to absorb electrons. These additional pathways for the free-flowing electrons translate to more electricity produced per absorbed watt of sunlight—and that means higher efficiency levels.

Also thanks to NeON’s cell characteristics, the panels are highly efficient even in low-light conditions, such as mornings and evenings.

The NeON® R and Back Contact Technology™

The NeON® R is LG Solar’s high-power luxury panel featuring up to 21.4% efficiency thanks to our newly developed Back Contact Technology. The advanced cell structure of the NeON® R locates all of the panel’s electrodes on the back side, reducing power loss resulting from shading. This boosts the panels’ capacity for light capture and overall efficiency.

As with the NeON® 2, the electrons absorbed by NeON® R panels are funneled into numerous pathways instead of the usual three to reduce power loss and increase power output.

Conclusion:

Why Efficiency Matters?

When homeowners consider their choice of solar panels, they look at a variety of features, from aesthetics and durability to maximum power output and warranty policies. Efficiency is one of the most important considerations. High efficiency panels produce more power in a smaller space over a variety of sunlight conditions. As a result, fewer panels are required to produce the same level of power output (which gives installers more flexibility when designing arrays for smaller roofs or in shaded areas).

Balancing the investment in the cost of solar panels with their efficiency rating and maximum power output, consumers gain both short-term and long-term benefits from purchasing high-efficiency solar panels. LG Solar’s BiFacial, NeON® 2, and NeON® R panels provide solid options for arrays ranging from small rooftops to large commercial installations.

_ Provided by LG Solar

A Journey To A Net Zero Energy Home

Solar Panel System with Battery Storage

As the extreme weather event such as heatwaves, hurricanes, floods, wildfires, drought, and rising sea levels is emerging, rooftop solar panels offer an affordable solution to restore natural systems with renewable, carbon-free energy. Distributed solar offers tremendous potential to reduce our nation’s GHG emissions, and large deployments will also reduce sulfur and mercury pollution while saving approximately 60,000 American lives each year.

One remarkable net zero energy project that had a positive impact on the community, the environment, and our company is the Starkey solar project.

Background

Gil (James) Starkey is co-founder of 350 Austin, a nonprofit organization fighting the climate crisis. He has dedicated his energies to inform people about global warming while personally taking on the climate crisis by shifting his reliance away from fossil fuels and moving toward clean energy with rooftop solar, a battery system, and a fully electric vehicle.

Starkey and his wife Roberta Tsurkahara have been interested in solar and energy conservation for a long time. They had solar on the home prior to their move to Texas and were familiar with the benefits when they purchased their new home in the Mueller neighborhood. Installing another rooftop system seemed like the right thing to do. They have owned their current system for three years now and are contributing to a more fossil-fuel-free world.

Since their home was newly built, they were not certain what their energy needs would be, but they wanted a photovoltaic system projected to offset over 90% of their consumption. After some discussion and number crunching, they concluded a 7.5 kW system would be a good fit. The system produces an average of 10,705 kWh yearly by utilizing 25 LG 300W AC modules. However, the Starkey family has managed to consume less electricity than the average home of its size. The result is they produce more electricity than they use and the family has yet to pay an electric bill. 

This year, with federal incentives scheduled to decline in 2020, the Starkey’s decided to make their next big investment by purchasing an electric vehicle and a battery system. With two Tesla PowerWall batteries, they can manage their entire home electricity consumption and monitor their usage. Battery storage is another tool that helps the Starkey family deal with climate change and manage their way through blackouts.

Tesla

Power

Wall

& EV Charger

Customer Interview

I had an opportunity to ask Gil a few questions about his solar journey.

 Nafi: What interested you about going solar initially?

Gil: Having lived most of my adult life in the Boston area, we had no real opportunity for solar power, since we lived in urban condominiums. These buildings ranged from 70-110 years old and were difficult at that time to retrofit for solar.  I became interested in solar when I moved to Austin in 2000 and built a house. Our interest at the time was to limit, as much as possible, our direct impact on the environment. Generating our own electricity was, therefore, appealing.

We were not able to implement solar before returning to New England, this time to an ecovillage in Maine.  We installed solar there for the same reasons we had planned to do so here in Austin.  By the way, we were in mid-coast Maine, where wintertime overnight lows are quite frequently below zero, often 10-15 degrees below zero. Our house was designed to approach the Passive standard, so it was extremely well insulated and faced solar-south to maximize passive heating.  Because of these factors, our home had to be, and was, 100% electric, even in a frigid climate.  Our solar panels enabled us to live very comfortably at nearly net-zero. That experience sold us on solar panels.

By the way, solar panels were cropping up all over Maine on 100 to 150-year-old farmhouses. I was surprised to learn that although Maine receives much precipitation and experiences many cloudy days, it actually receives more sunshine than Germany, where solar panels are ubiquitous.  No wonder Mainers, thrifty New Englanders that they are, were installing solar!

Nafi: How did you choose a solar installer?

 Gil: Having already decided to go solar once we returned to Austin, I began researching companies as soon as we knew where we were going to live.  My research narrowed things down to a few companies and my decision was confirmed when I discovered that our neighborhood had gone through a selection process for a significant solar project a year or so before we moved in.

Nafi: What advice would you give to someone who wants to go solar?

Gil: First of all, it just makes sense from economic, environmental, and climate change perspectives. Texas is absolutely bathed in sunlight. I am baffled that governments and electric utilities do not promote and subsidize solar more strongly. The more solar people install, the fewer utility-grade power generation facilities must be built, and that alone will save utilities hundreds of millions of dollars.

The price continues to plummet. Two years after installing solar in Maine, we purchased a system here that was 40 percent larger, but the net price of the two systems was the same. We (humanity) must move to a zero-carbon economy at warp speed. Global heating is approaching tipping points that once crossed, cannot be reversed. Utilities have traditionally contributed the most greenhouse gases, so widespread solar (and wind) generation is a necessity. It makes sense. Do your research. Find a strong, reputable company, and get a proposal.

 Nafi: Do you have any data on your solar system’s performance you found it interesting to share?

Gil: Our system was intentionally over-engineered because we planned at some point to purchase an electric car. We now have our EV, and I am pleased to report that our solar array is supplying all of our home's electricity, even in summer, plus charging the car. We are effectively off-grid for home and transport. Since installing solar in February 2016, we have not paid any utility bills. That’s right, $0, and we have a substantial credit with Austin Energy.

Without a rooftop solar system, they would have paid approximately $1,243 per year for the electric bill. Moreover, the solar panel system cost will be paid off within 8 years and the total amount of money the household will save within 30 years is estimated at $41,785.

Net Zero Energy Home: Austin,Texas

Solar+Storage Data Monitoring: a Strong Tool to Manage Usage

 Everyone is familiar with data collection trends and the ways in which information is used and misused; from sabermetrics in baseball to news blasts on Facebook. But when it comes to conserving energy in your home, energy monitoring tools are extremely useful. These tools are available for consumers to monitor the production of their photovoltaic systems and the energy consumption of their home or business.

 The ability to see and use consumption data enables the Starkey’s to make informed decisions about their electricity use— knowledge is power when it comes to conserving energy. Online monitoring tools enable customers to access information from their browser or smart phone. After three years of monitoring, the Starkey system has offset 100% of their home electricity consumption. This could change next year with the additional EV home charging load; time will tell.

The graph illustrates the electricity generation and consumption for two summer days related to the Starkey family solar system. Despite the higher consumption in the summer time and using an EV charger the production still matches what the household demands.

Conclusion

The United States installed 2.7 gigawatts of solar in the first three months of this year, which set a record for the first quarter of a year. In addition, 25 percent solar growth is predicted this year by Wood Mackenzie Power & Renewables institute. According to Renewable Energy World Texas holds great potential to increase renewable energy generation and to integrate distributed solar resources in innovative ways while preserving our deregulated market structure. Collective action is all that is required to move and make Texas green.
If you would like to learn more about Lighthouse Solar services or be a part of the green movement, contact us at Lighthouse Solar for a free estimate and consultant.

Click HERE or call us at (512) 476-5555.

- By Nafi Shah & Jay Bramble