LG Chem Battery Vs. Tesla Powerwall

There’s no shame in referring to solar power as “Source of unlimited energy”. Solar power provides clean energy for the masses as the sun delivers more than enough energy to power up everything on our planet. There’s no better time than now to invest in solar power for your personal households. There are multiple benefits of investing in solar power. When you invest in solar power, you’re effectively helping in saving the atmosphere of our planet earth. Plus, in the long term, investing in solar power can save you a lot of money. The photovoltaic process that transforms sunlight into electricity doesn’t require any fuel for its functionality. There’s no harmful emission of carbon dioxide in the atmosphere when electricity is produced from solar panels. Moreover, the electrical energy produced by solar panels is renewable because the only thing needed is sunlight, which is available in a surplus amount throughout a sunny day.

If you’re settled in Yakima, Bellevue, Tri-Cities, or Walla Walla and are willing to put your money in this long-term investment, Solora solar could be your best friend.

Battery Backup Solar Systems:

Before we go on to compare LG Chem batteries and Tesla Powerwall, it’s important to understand what exactly these are and why they are even used in the first place. A Battery Backup-grid tied solar system stores the extra electrical power which is not being used by your appliances into battery banks. And these battery banks, you guessed it right, are LG Chem batteries and Tesla Powerwall.

When your solar panels aren’t generating electrical energy (during cloudy days or nighttime), the energy stored in battery banks of your Battery Backup solar system is used to power your appliances. Battery Backup solar systems are more expensive than other solar system solutions because you have to invest in batteries and inverters. However, the cost of these batteries is coming down at a rapid pace, making Battery Backup solar systems more popular and accessible to the masses.

Now, as you’ve got a clear understanding of Battery Backup solar systems and the role of these batteries in them, let’s move on to compare LG Chem batteries and Tesla Powerwall.

Of course, if you need any technical help or assistance regarding off-grid solar in Yakima, Bellevue, Tri-Cities, or Walla Walla, you can always get in touch with Solora Solar.

Battery capacities:

The capacity of your solar system’s battery could be a major deciding factor for you. Everyone has unique requirements, that’s why it’s important to choose the right battery with the right battery capacity for your specific requirements.

The capacity of a Tesla Powerwall 2.0 is 13.5 kWh. It’s the highest solar battery capacity available on the market. If it’s still not enough for your requirements, you can stack up to 10 Powerwall batteries together to get even more power storage capacity.

On the other hand, LG Chem Resu batteries come in 5 different storage capacities. These capacities range from 2.9 kWh to 9.8 kWh. These batteries are ideal for smaller and larger Battery Backup solar systems because of their wide storage capacity range. They are also ideal for your unique-sized power storage needs because of the capacity variety available in them.


Tesla powerwall are higher in cost specially if you add other equipment that you need to connect with your PV system with Tesla powerwall to use as a backup option.

LG Chem batteries are more economical and doesn’t require additional equipment since these are designed as DC couple system and control (Battery Management System) via inverter i.e. SolarEdge inverter and very easy to install, hence less labor cost.


If the storage technology of your solar system concerns you, let’s inform you both of these batteries use lithium-ion technology. Hence, no difference in this sector.

Uninterruptible power supply:

One of the benefits a Battery Backup system is that it offers an uninterruptible power supply. In case of a power cut, the LG Chem battery and Powerwall keeps working as if nothing happened.


There’s nothing to worry about here, both batteries offer a warranty of 10 years. However, in the rare case of a fault development in LG chem battery, 100% of the price will be covered by LG if the fault happens within 2 years of the installation. If the unit has been installed for 3 years and it develops a fault, only 72% of the price will be covered by LG.


Both of these batteries support floor-standing and wall-mounting. So, you can’t go wrong with any of these in this regard.


The Tesla Powerwall is completely weatherproof and is compatible with outdoor installations. You can confidently install it indoors or outdoors, depends on your preferences and needs.

LG Chem batteries, on the other hand, are IP55 weather rated. They can only be installed in semi-outdoor environments like a carport or verandah.

Which one is the winner?

Well, there’s no absolute winner when it comes to comparing these two batteries. Both of these batteries have their pros and cons. However, let’s put this straight for you.

Tesla Powerwall is AC couple battery system meaning it can be added or retrofit with existing Grid-tied solar energy system, and in the future, if your storage requirements increase, you can stack up to 10 of these batteries. It’s safe to say, Tesla Powerwall grows as your storage requirements grow.

On the other hand, if your residence is smaller and you need something which can fulfill your specific needs, LG Chem battery could be your ideal choice due to its huge variation of storage choices. LG chem is a DC couple battery, meaning it can only be installed with new Grid-tied Solar energy system and does provide much more efficient power conversion.

Need help?

After you’re done choosing one of these battery banks for your off-grid solar system and are ready to get one installed, that’s exactly where Solora Solar can help you. Need any assistance regarding solar in Bellevue, Yakima, Tri-Cities, or Walla Walla? Solora Solar is at your disposal.


Keywords: Off-Grid Solar, Solar in Yakima, Solar in Bellevue, Solar in Tri-Cities, Solar in Walla Walla


Designing a structurally sound solar system is one of the biggest challenges for solar contractors today. Solar arrays can be exposed to the worst weather conditions; including high wind, hurricanes, snow and hail. These systems need to be able to withstand the wind loads in their specific locations if they are to remain in service for up to 25 years. Solar panels are extremely durable and can withstand severe and harsh weather conditions when mounted correctly. Although you may wonder, how do we design mounting systems to be resilient to these extreme wind forces or even not so extreme windy conditions as it was the case in recent incident in Yakima, WA @ Firman Pollen Co building.

“Recent high wind (gusty wind up to 50mph) has blown away Solar panels and bricks from buildings near North First and West Lincoln Avenue”.  It was quite shocking to read this news in Yakima Herald, because Solar Array usually don’t fall off and should not fly away with 50mph gutsy wind as long system is properly design and install, even if it’s designed with minimum load requirement regardless of local AHJ permitting and installation criteria.

Roof-top solar arrays are increasingly being deployed on buildings across Central Washington in past decade, as the basic economics of PV generated electricity improves. Assuring that the building structures can withstand the additional loads imposed by PV arrays on roofs has become a key issue in the deployment of these systems, and therefore a key question for structural engineers and building officials responsible for reviewing and approving such systems.

In Central Washington, the basic wind load requirement for roof mount solar is 110 mph exposure C with system distributed weight less 3psf. The system is question seems to have “Ballast Roof Mount system” meaning it wasn’t physically attached to roof structure and held down by Ballast/ concrete block. This type of design mainly used on commercial flat or low pitch roof and perfectly within scope of design. However, these types of system generally add more load on the roof, sometime more than 5psf which is in most cases much more than building structural design load and require structural engineering analysis and/or retrofitting to support the additional load.

In many jurisdictions in the United States, there can be little regulation for ensuring structural stability of the PV racking system. This causes a great deal of confusion for installers, as they are responsible for knowing their own jurisdiction’s regulations and they can’t always rely on computer designed bill of materials or production programs to correctly design systems according to those regulations. In ASCE 7-5 and 7-10, a section called components and cladding has been used in many jurisdictions as a reference on how to design and permit solar arrays on buildings, with all this confusion, PV system can be installed with sub optimal design either purposely or due to lack of understanding.

There are a multitude of factors that go into designing a system that can survive harsh weather events. It is important to understand what some of these major factors are to mitigate risks associated with wind-related failures.


Roof zones determine the amount of wind load that is subjected to the system based on where the system is located on the roof.

Zone one has the lowest load and consists of the interior space on the roof. Zone two represents the perimeter of the roof and is a higher risk zone.

Zone three is located on the corners of the roof and is the highest risk area. Most system failures occur on the edge or corner of the roof. Installing modules on the edge or corner of the roof can be dangerous and risky. In many cases, installations in corner or edge zones require more attachment points or ballast. Even residential installations in low-risk areas, like California, may require shorter spans with increased attachment points in corner zones. Calculating roof zones can be challenging depending on the code used in a specific jurisdiction. It is best to consult the appropriate code and consult the engineer or the racking manufacturer may have software that can assist with the zone calculations. For example, we here at Solora Solar t have been using our manufacturer design tool IronRidge for roof mount and SnapNrack design tool for ground mount solar. We provide these calculations not only to AHJ during permitting and inspection process but as well as to our customer for their record.


More precautions need to be made based on the importance factor of the building. Building codes classify buildings by risk of human life, health and welfare. You can refer to ASCE 7 provisions to determine appropriate classifications. For example, a building like a barn would likely represent risk category one due to the low risk of life lost in the event of a failure.

A hospital would be categorized as a level four risk due to it being a building necessary to human life. Most PV systems are installed on risk category two structures. The structures included are typically houses, business warehouses, restaurants and hotels. PV systems on risk category three and four buildings are expensive. This is due to the required additional ballast or attachments to mitigate risk of failure. In many cases, these systems cannot be installed in roof zones two and three on risk category three and four buildings. These additional requirements can limit the amount of PV that can fit on the roof. For attached systems, adding more anchors than necessary can lead to water leaks and more costs down the road.


The wind loads on a PV system increase as the building gets taller. Any residential project that exceeds 30 feet typically requires custom engineering. It is important to understand the risks associated with installing PV on roofs that exceed 30 feet. This is especially true for instances on buildings such as hotels, that get up to as high as 100 feet tall. In many of these cases, the engineer of record will require anchors instead of a ballast to mitigate risks of failure.

Racking and anchoring systems are key to determining wind resiliency. If too little ballasts are used, (as it may have happened for the system in questions in Yakima), the array can flip or move when faced with strong winds. Tilted racking systems are typically more susceptible to higher wind loads than flush-mounted systems. In the case of ballasted systems, it might seem wise to simply increase the ballasts to reduce risks. However, there are risks in over-designing the system as well. Too many ballasts can cause structural issues with the building; especially those that experience seismic or heavy snow loads.

It is necessary to avoid these ahead of time and plan your systems using the appropriate codes for your specific jurisdiction. It is important to evaluate equipment and attachment methods to ensure that PV equipment will remain attached to structures during windstorm events, and that additional loads or load concentrations do not exceed the structural capacity of the building. It isimportant for design professionals to stay current with existing codes and standards, because we expect the body of information about designing PV systems to withstand local wind loading to grow rapidly in the near future.




More Questions Answered on New Solar Incentive Program

We are doing our best to keep our customers and readers informed about the new solar incentive package passed by the state legislature this year. We have already provided an overview of the new incentives now available, and this month the Washington State University Energy Program has published its own summary with answers to frequently asked questions.

The six-page document answers a wide range of questions, with heavy emphasis on questions about the application process, which is being administered by the WSU Energy Program. To read the view or download the document as a PDF, click here.

Utilities Considering Changes to Net Metering

As more and more homeowners and businesses make the decision to go solar, utilities are adjusting for the changes to the marketplace and considering revisions in policy and practice. One of the most serious changes being contemplated right now is the change to net metering.

Net metering is the practice whereby a utility customer with a grid-tied solar installation sells excess power back to the utility. Until recently, most utilities have compensated customers producing excess energy at market rates — that is, if the utility sells electricity at 10.45 cents per kilowatt hour, it will pay its solar customers the same rate, 10.45 cents per kilowatt hour, for any extra energy it buys back from them.

But as the number of utility customers selling back their solar power continues to increase, this practice has started to more significantly impact utilities because they typically pay much less for the non-solar electricity they sell to their customers.

The proposed changes to net metering is a nationwide phenomenon. Both utilities and state governments across the country are considering “alternative compensation structures,” according to pv magazine USA. The magazine notes that utilities and state governments in nearly half of all US states are considering or have made changes to net metering policies, and that these policies could discourage people from adopting solar.

In Washington state, Snohomish PUD is the most recent utility to go on record with its desire to modify net metering compensation — a representative of the utility telling the Everett Herald that the utility is considering altering the rates at which solar customers sell and buy back electricity or the possibility of charging customers a base rate.

While it’s not clear what kind of sell-back rates solar customers could get in the future, one thing is clear: The sooner home and business owners covert to solar, the better. For one thing, sell-back rates for the foreseeable future will remain at retail rates, as it will take some time for a net metering change to be pushed through. Second, Snohomish PUD and others have said current solar customers would be grandfathered and allowed to keep their current net metering arrangements.

That, plus newly passed solar incentives in Washington state, means going solar now perhaps makes more sense than ever.

Photo credit: Everett Herald

New Washington State Solar Incentive Program Details

Now that the so-called Solar Jobs Bill has been adopted by the Washington State Legislature as part of the state operating budget passed last month, solar owners and installers are starting to get a picture of what new incentives will mean for home and business owners who rely on solar systems to power some portion of their monthly electricity needs.

Existing Solar Owners

Existing solar owners can expect to be paid at the same rate they were paid by their utility in 2016. There are no reductions to this rate, but the program ends on June 30, 2020. Additionally, some additional paperwork may be required to keep incentives flowing.

Up to this point, incentives have been administered by the state Department of Revenue and will continue to be until Sept. 30, but starting Oct. 1, administration transfers over to the Washington State University Energy Extension Program. Because of this, existing solar owners must reapply to WSU by April 30, 2018 in order to finish participation in the program through the June 30, 2020 end date.

Incentive payments remain limited to $5,000 per participant per year. Systems under 10 kilowatts are exempt from sales tax, while systems 10 kW or greater are eligible for 75 percent remittance.

Although the legacy program is technically limited to projects completed by June 30, 2017, there is a short window from July 1 to Sept. 30 when solar customers may opt to enroll in either the existing program or the new program. Starting Oct. 1, all solar projects will only be eligible for new incentives.

Future Solar Owners

Future solar owners are encouraged to act quickly, as the new program incentives step down each year from 2018 to 2021. Projects are eligible for a base rate plus a bonus if solar panels were manufactured in Washington state.

Year Residential Base Rate ($/kWh) Commercial Base Rate ($/kWh) Made-in-WA Bonus ($/kWh)
2018 $0.16 $0.06 $0.05
2019 $0.14 $0.04 $0.04
2020 $0.12 $0.02 $0.03
2021 $0.10 $0.02 $0.02

Under the new program, solar owners receive the same flat rate over the life of incentive payments, determined by the year when the project was completed. Incentives run for eight years or until 50 percent of the project cost is recouped, whichever occurs first. Projects 12 kW or smaller are capped at $5,000 per year, while projects larger than 12 kW may be paid up to $25,000 subject to a 25 percent program cap on total funds for these larger (usually commercial) projects.

Sales tax is required to be paid under the new program for all systems under 500 kW, while systems 500 kW or larger are subject to 75 percent remittance.

Full details are available on this handy summary produced by the Solar Installers of Washington.

New Solar Incentives Passed by WA Legislature

If you have been contemplating a solar installation for your home or business, but weren’t sure whether the incentives would be there to help finance the investment — your wait is over, as new solar incentives in Washington state officially become available tomorrow.

That’s because the Washington state House and Senate today passed legislation that had become known as the Solar Jobs Bill as part of their $43.7 billion state budget package, which came after multiple special sessions and narrowly averted a partial shutdown of state services.

“We didn’t just pass a bill,” Bonnie Frye Hemphill, campaign director of Keep WA Solar Strong, said in a statement. “Together, we built a community of 10,000 people passionate about clean energy and energy independence.”

The bill replaces outdated incentives for solar owners with a new program designed to boost incentive caps for public utilities, who can make their incentives available to homes and business in their districts. The bill offers a new incentive payment schedule for solar owners that starts at $0.16 per kilowatt hour (kWh) and adds bonuses for systems with solar panels manufactured in Washington state.

While more details about the new solar incentive program will become available in the coming days — and it will take some time for various utilities to put their incentive packages together — owners of homes and businesses in Washington state should know that they can move forward with plans to go solar with the support of incentives that officially become available July 1.

If you are interested in exploring the installation of a solar system tied to the grid of your local electric utility in Washington state, drop us a note on our contact page or give us a call at (800) 696-8935.

Photo credit: Jim Bowen

State Legislation Would Boost Incentives for Solar Owners

Proposed legislation in Olympia could increase the incentives available for solar installations in Washington state if approved by lawmakers during this year’s special session.

The Solar Jobs Bill (House Bill 1048/Senate Bill 5499) would bring an end to the outdated Renewable Energy System Cost Recovery Program on June 30, 2017, and would replace it with a new program designed to increase incentive caps for utilities and offer new incentives for homeowners, businesses or government entities who own solar installations or participate in community solar projects.

Under the proposed program, utilities would be able to claim a minimum annual credit of $100,000 up to a half a percent of the utility’s total power sales. This credit would be made available for utility customers to apply toward qualifying solar systems under the new program.

The new cost recovery program for solar owners allows for incentive payments starting at 16 cents per kilowatt hour (kWh), increasing another $0.08/kWh for using solar panels manufactured in the state of Washington for a maximum incentive rate of $0.24/kWh. For community solar installations — for people whose rooftops aren’t right for solar or who don’t own their homes — the rate increases to $1.08/kWh.

Sponsored by Rep. Jeff Morris, D-Mount Vernon, HB 1048 has been designated “necessary to implement the budget,” which means it will be considered as part of the budget approval process. A companion bill in the state Senate, SB 5499, similarly seeks to re-establish healthy solar incentives.

Numerous organizations, from environmental groups and faith communities to utilities and labor unions, are supporting the so-called Solar Jobs Bill with a sign-on petition led by the Solar Installers of Washington. The group is offering information and suggestions on contacting legislators at SolarStrongWA.org.

Photo credit: Governor Jay & First Lady Trudi Inslee

Rooftop Solar Cools and Reduces Thermal Stress

With spring in full swing, the clouds have just started to give way to glorious sunshine. Soon things will be heating up. When considering the overall efficiency of your residence or commercial building, a roof-mount solar installation may be able to help you beyond the generation of clean energy and savings in electrical utility bills.

That’s because one often overlooked benefit of a solar install on your roof is the way the panels act as a shield from the heat of the summer sun, resulting in cooler temperatures inside. In fact, researchers from the San Diego campus of the University of California concluded that the daytime temperature of a ceiling inside a building averaged “5 degrees Fahrenheit cooler under solar panels than under an exposed roof.”

In fact, the study found the money saved in air conditioning costs was worth roughly 5 percent the price typically paid for solar modules. Obviously the panels themselves are a barrier to the sun’s heat — reducing the amount of heat reaching the roof by 38 percent in some cases — but there are other factors in play as well.

“Much of the heat is removed by wind blowing between the panels and the roof,” researchers reported, adding that greater cooling effects are achieved with a tilted solar panel install and with high-efficiency solar modules.

At night, the study said, solar panels allowed buildings to keep the heat accumulated inside due to insulating properties of the panels. The study concluded that the reduced “variability” in rooftop temperatures “reduces thermal stresses on the roof and leads to energy savings and/or human comfort benefits.”

So if you’ve been pondering a switch to solar, here’s yet another reason why solar could be a great investment for your home or business. If you would like a free energy assessment, get in touch with us at Solora Solar today.

For more information on the UC San Diego study, we recommend a couple of great summaries at TreeHugger and EarthSky. You can read the full study on ScienceDirect.

Three Months Left to Cash In On Snohomish PUD Solar Incentives

If you have been considering going solar and happen to live anywhere between Lynnwood and Stanwood — that is, Snohomish County — you might want to go green before the greenbacks are gone.

Snohomish County PUD has announced that their Solar Express program will be sunsetting on June 30, 2017. This means residents of Snohomish County and Camano Island have just three months to get their residential or commercial solar project submitted in order to receive up to $2,000 in incentives for residential installs and $8,000 for commercial installations before the incentives expire.

The specific rebate Snohomish PUD offers for solar projects is $300 per kW. Projects must meet certain requirements, one of which is that the installation site must capture at least 75 percent of direct sunlight when taking into account orientation, shade, tilt and other factors.

If you would like to get more information about the expiring program, visit the Learn About Going Solar page on the Snohomish PUD website. If you would like a free estimate on your project from Solora Solar, give us a call at (425) 366-8953 or tell us on our contact page.

If you don’t live in Snohomish County but are curious about incentives, give us a call. In minutes, we can usually tell you the federal, state and local incentives for which you may qualify.

Printing Solar Panels on Our Curtains? Don’t Blink, It May Happen

Could it be possible one day to hit the “Print” button on your computer and generate a sheet of… solar panels? Will we someday peek through solar panels printed on our curtains and blinds to see if it’s nice outside?

The phenomenon is not as far off as you might think. According to the Australian website Habitat, it is already possible to print solar cells with inkjet printing. Scientists believe it won’t be unusual someday to print cells on a variety of surfaces, including walls, umbrellas, tents and windows. And developers of clean energy in Seattle are already experimenting with the process in a new clean energy lab that opened this month.

Printable solar cells are made by printing a special type of photovoltaic film on a plastic surface. The product is much cheaper than purchasing the solar panels that have been used on the roofs of homes and businesses for years, but it also has a ways to go in terms of efficiency — paper cells are about 10 percent efficient, compared to an efficiency rating of around 25 percent for PV solar panels.

“Silicon is falling in price, but think about how cheap plastic is. The ink is a negligible cost, so the raw materials are very cost effective. This is a big step forward because you can put these cells anywhere you can think of. Also the consistency is better than silicon — they work well in cloudy conditions,” photovoltaic expert Dr. Fiona Scholes is quoted as saying in Habitat.

In Seattle, testing has begun on the process at the newly opened Washington Clean Energy Testbeds. The facility’s director, J. Devin MacKenzie, told the Everett Herald the new technology would not only be more affordable, but it could be produced much faster and create less waste.

“This would take an hour to go from a new design to printing something structurally,” MacKenzie told the newspaper.

Photo credit: Habitat