Batteries

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Inverter Partners

Authorized Dealer of Premium Inverter Products

How would you characterize the short-term outlook for solar in Hawaii?

In the short term, solar installations in Hawai’i may slow somewhat. As understanding of the new HECO program grows, and the public becomes aware of available options, the solar industry will pick up again.

 

Will cap halt residential solar altogether?

As Mark Twain allegedly once said, “rumors of my demise have been greatly exaggerated.” This holds true for solar as well. With new technologies and lower and lower equipment prices, the solar companies and their customers will find ways to work with onerous regulations and arbitrary limits imposed by HECO and the PUC.

 

Will some solar companies go out of business? Do current solar owners need to be aware of this due to service and warranty fulfillment?

Some solar companies will most likely close their doors. Those that embrace newer technologies and find creative ways to work with HECO will continue to thrive. Solar company closures may impact service and warranty contracts. Be sure to use a reputable installer that utilizes established brands as the longest and most important warranties are through equipment manufacturers. Also keep in mind that a sub-par installation by a company that has gone out of business can create numerous and expensive problems down the road. An amazing deal today might not look as great 5-10 years from now when facing costly repairs.

Old ROI versus new ROI? How long will it take to reach 100%?

For residential customers, typical ROI will now be somewhere around 8 to 10 years. However, with the new DER program, ROI will depend heavily on a customer’s usage profile (i.e. when they use power). The more a customer can use during daytime hours, the higher and quicker the ROI will be.

For commercial customers, whose majority of use occurs during the day, ROI will probably be around 3 to 4 years.
These figures are now more in line with the mainland. Clearly, ROI figures like this have not slowed solar in areas like California and the Southwest. Solar is even thriving in the Northeast, an area not typically associated with an abundance of solar resources.

Because of this, we believe Hawai’i will continue to be a leader in the solar industry.

 

How good are batteries now? What are some things people should look for in batteries?

Truly viable battery technology has arrived! With a flurry of investment over the past few years by established global companies like Sony and well funded start-ups like Aquion, battery technology is better than ever and represents a real alternative to grid power in certain applications. There are several factors to consider when buying batteries:

Use: How will you use your batteries? Are you looking for a battery to back up critical loads in case of utility outage or do you want to go off grid and cut your connection to HECO altogether? Or perhaps you’re a business owner looking to decrease HECO demand charges (also known as peak shaving). Different types of batteries are better suited to different uses.

Safety: Most batteries are stored inside your home or business. Well-publicized incidents of battery fires have created legitimate safety concerns for certain types of batteries. Furthermore, some batteries contain hazardous chemicals like sulfuric acid and can off-gas when charging and discharging, requiring external ventilation. Be sure to research battery technology and chemistries to determine their safety record and material composition.

Maintenance: Are you willing to do regular maintenance or do you let your car go 20,000 miles between oil changes? Some batteries like traditional lead acid require watering and equalizing on a monthly basis (old timers like me remember those in dad’s old car). Other batteries require no maintenance at all.

Modularity: Like most people, your energy demands fluctuate. When a new baby arrives or auntie moves in, you need more power. Certain kinds of batteries can be easily expanded and others cannot.
Energy Density: If you have unlimited space to store batteries, this isn’t an issue. If you don’t, energy density (how much charge a battery can hold for its size) can be very important. Some batteries technologies provide great energy density; others require lots of space in your garage or storage room.

Durability/Reliability: Like the battery in your car, certain batteries last a few years, others can last over twenty years. Likewise, some batteries are manufactured to be completely, or almost completely discharged. Other batteries can only be discharged a certain percentage. For example, traditional lead acid batteries cannot be discharged more than 50% on a regular basis without significantly shortening their lifespan. So, look for a battery rating and a good warranty. Battery ratings will be given in the number of cycles, or how many times the battery is discharged then recharged. For a home PV system, this generally occurs once a day. Then look for the depth of discharge given in a percentage. Examples will look like this: 3000 cycles at 100% depth of discharge or 3800 cycles at 40% depth of discharge. Most batteries have a 3 to 5 year warranty and a few come with as much as a 10 year warranty.

Battery Bank Sizing: This is a tricky one and has been the source of premature death for thousands of batteries. There are several factors that go into sizing a battery bank including: your current and future loads (usually discussed in terms of kWh used per day), your current and future load profile (usually discussed in terms of kW being used at any given time), battery specs, battery performance characteristics, and so on. The best way to size your batteries is to accurately measure your loads with a monitoring device that can upload this data to the web. Installers then plug that data into sizing programs that take other factors into consideration like to accurately size your battery bank. As discussed in Question #3, your best bet is to find a reputable company that will install quality products that will last for years.

And last but not least,

Price: This might seem simple but isn’t. At first glance, a battery bank that costs $7,200 is a much better deal than a battery bank that costs $14,000 if both provide the same amount of power per day. However, it’s important to look at lifespan and price per kWh (kilowatt hour). Let’s say that each of the batteries above provides 12 kWh of useable energy per cycle (see section vi). The first battery has a lifespan of 7 years and will provide 30,660 kWh’s of energy (12 kWh x 365 days x 7 years) for a price of $7,200. The second has a lifespan of 20 years and provides 87,600 kWh’s of energy (12 kWh x 365 days x 20 years) for a price of $14,000. The price per kWh for the first battery is a little over 23 cents. The price per kWh for the second battery is less than 16 cents. After calculating price per kWh, the second battery bank is actually a much better deal.

How often do I have to take care of batteries?
It truly depends on the tech of the battery. Lead acid batteries, 5-10 yrs ago, took a lot of maintenance and some electrical know how to maintain the battery. Some of us who remember the good old days of refilling our batteries with distilled water is somewhat a thing of the past. New tech that includes AGM, FLOW, Sodium Ion, Lithium Ion Kobalt, and Lithium Iron Phosphate batteries take the thinking and the maintenance out of the equation. So to answer the question, depending on the equipment you buy will depend on how much maintenance is required for your battery. Also each battery has a max cycle period. Some max cycles are 3,000 cycles, some are 5,000 cycles, and some are 8,000 cycles, and more. Each cycle depends on how much you can actually Discharge a battery. Most lead acid batteries usable energy is only 50% usable. What does that mean? Well, a 5kw lead acid battery would only be a 2.5kw usable battery. This is considered one cycle. So what about Lithium Batteries? Well depending on what chemistry you buy will depend on how much you can discharge your battery. Chemistries like Lithium Kobalt batteries recommend state of discharge should be only 70% because of the thermal runaway of the battery. So for example, a 10kw Lithium Kobalt batteries usable energy is only 7kw. That would be one cycle of the Lithium Kobalt battery. Is there anything better than that? Yes, Lithium Iron Phosphate batteries are able to discharge 100% and so a 10kw Lithium Iron Phosphate usable energy is 10kw.
What do I do if I want to add more appliances?
If you’re adding an appliance to your battery system. You would need to contact your contractor to check if your current system will handle the load. Unlike having a utility to provide you with a large source of energy. Having your own independent system means being independent/supporting the grid.
What happens if I drain the system?
Depending on what system you purchase will depend on how much and how fast you drain those batteries. The more energy use over time will depend on how fast you deplete your system. Also the more loads you add means the faster you will deplete your batteries.
**New tech that includes AGM, FLOW, Sodium Ion, Lithium Ion Kobalt, and Lithium Iron Phosphate batteries take the thinking and the maintenance out of the equation. So to answer the question, depending on the equipment you buy will depend on how much maintenance is required for your battery. Also each battery has a max cycle period. Some max cycles are 3,000 cycles, some are 5,000 cycles, and some are 8,000 cycles, and more. Each cycle depends on how much you can actually Discharge a battery. Most lead acid batteries usable energy is only 50% usable. What does that mean? Well, a 5kw lead acid battery would only be a 2.5kw usable battery. This is considered one cycle. So what about Lithium Batteries? Well depending on what chemistry you buy will depend on how much you can discharge your battery. Chemistries like Lithium Kobalt batteries recommend state of discharge should be only 70% because of the thermal runaway of the battery. So for example, a 10kw Lithium Kobalt batteries usable energy is only 7kw. That would be one cycle of the Lithium Kobalt battery. Is there anything better than that? Yes, Lithium Iron Phosphate batteries are able to discharge 100% and so a 10kw Lithium Iron Phosphate usable energy is 10kw. **
Do you charge for service calls? How much?
Yes, depending on the issue at hand.
How much space will batteries take up?
Depending on the model or chemistry you buy will determine the density and size of the battery. The usual lead acid battery will be less dense than a Lithium Ion battery. The size and space that a lead acid battery will consume is usually 3 to 4 times larger than a Lithium Ion Battery.
What makes your Company different from the others?
What makes Hi Power Solar different is that we invested our money into an off-grid system that powers our home office here in Oahu. Hi Power Solar wanted to power a whole house with 2 central Air Conditioning units, Electric Stove and Oven, Electric Washer & Dryer, lights, and refrigerator.
How much will I be spending to replace equip in 15-20 years?
Depending on your chemistry of batteries will determine the life of your battery. Lead acid batteries have life cycles of up to 2,000 cycles at 50% of depth of discharge, Sodium Batteries cycles up to 3,000 at 100% depth of discharge, Lithium Ion Kobalt batteries cycle 5,000-7,000 cycles at about 70% depth of discharge, Lithium Iron Phosphate batteries cycle 8,000-10,000 cycles at 100% depth of discharge. Depending on how you cycle your batteries every day will determine the life of the battery. A straight forward example is that a Lithium Ion Phosphate battery will last 8,000 cycles at 100% Depth of Discharge is for each cycle at a 100% Depth of Discharge equals 1 day of use. Lithium Iron Phosphate batteries last up to 20+years.

Off Grid inverters will last 5-10 years depending on the use and placement of the battery. Most off grid inverters have a 5yr workmanship warranty.

How long will it take to install?
1-3 days if it is a small system.
1-2 weeks if the system is large.