Understanding Solar Technology: Panels, Inverters, and Battery Storage

scanning: time:2021-09-26 classify:Technology info

solar panel1

There has been significant development in solar technology over the last decade. With more homeowners shifting to solar energy to save money and reduce carbon footprint, it’s good to learn about the technology that’s helping save thousands of dollars per year and increase home values. Sunny Energy discusses these technological advancements in the solar industry here:

Solar technology has rapidly evolved and seen a significant reduction in price, about 70% to 80% over the last decade. As a result, homeowners save a lot of money and get great returns on investment. If done right, solar is the only home improvement system that pays for itself even decades after its installation!

solar panel2

In fact, Sunny Energy customers often see a significant return on investment, with some reporting as high as 14%.

The Efficiency and Performance of Solar Panel Technology

Let’s have a look at the technology behind the savings. Efficiency is often used as the key solar panel characteristic, but overall performance is most important. Our top choice for solar panels is the award-winning REC Alpha Series solar panel which has high efficiency, looks great on the roof, and produces more energy than just about any other panel in its class! This high-performance series has heterojunction (HJT) cell technology and such features as:

  • No LID, which means no power loss, and you get the power you pay for.

  • Leading temperature coefficient, meaning that it produces more energy as temperature rises – a must-have in Arizona heat!

  • Lower degradation and power loss over time – guaranteed no more than 8% loss in 25 years!

  • Delivers around 20% more power from your roof than any other conventional solar panel!

In addition to the solar panels, each system also has an inverter. Essentially, a solar panel converts sunlight into DC energy. The inverter then converts this into electricity that you can use in your home. Any excess energy that you do not use in your home goes into the grid as well. So, give back to the environment by creating your own power and help out your neighborhood!

Sunny Energy uses SolarEdge inverter technology, which has the highest power conversion efficiency in the world.  Like micro-inverter technology, each panel is optimized and monitored for optimal power performance, but the power conversion components, which have been known to fail in micro-inverter technology, are not on the roof.  Not only do you get more energy, but you also have higher reliability!  And, for battery storage with solar applications, Generac inverters are also a great choice with similar characteristics.

Sunny Energy proudly provides homeowners with the latest solar technology on the market so that you’re able to take advantage of the benefits of creating renewable and clean energy – as well as storing it. 

The Power of Energy Storage

But what about nighttime? That’s where battery storage comes into play. When there is no sunlight, such as at night or on overcast days, battery storage can help. A homeowner with a battery + solar system can use their solar-generated electricity even after the sun goes down. These batteries also help offset the high-cost peak energy consumption at sunset or night.


Additionally, you can use this to power your home if the grid is out, like during monsoon season. If there is a power outage, the energy saved up from the battery would keep your lights on.

The SolarEdge or Generac inverter technology used at Sunny Energy is far ahead of the competition, with the capability of adding on battery storage, EV charging, and sophisticated energy management tools.

At Sunny Energy, we believe in providing our customers the latest tech and innovation in solar energy. We constantly look for different ways to integrate better and efficient tools to save money and reduce carbon footprint. We believe renewable and clean energy is the future.

solar panel3

A breakdown of how each part of the system works during the day

The charge controller will charge the batteries when there is sufficient power to charge them. Any extra power produced by the solar panels will be sent to the inverter. When the batteries are fully charged, the charge controller will cut off the charge going to the batteries except for a small float charge meant to keep the batteries fully charged. 

The charge controller and batteries 

With sufficient sunlight, the solar panels provide electricity to the system. Power provided to the solar charge controllers from the solar panels will be used to recharge the batteries. The amount of voltage, known as the nominal voltage, needed to charge the batteries rises as the batteries charge. As a result, the charge controller will increase its output voltage as the level of charge in the batteries rises. When the batteries are fully charged, the charge controller maintains a trickle charge to hold the batteries at their full charge.

When the sun isn’t shining, the charge controller will block current from flowing from the batteries to the solar panels. This prevents the batteries from discharging into the solar panels.

The battery charging process

To keep things simple, imagine we are charging a 12-volt battery. A 12-volt solar panel is used to charge a 12-volt battery. But that solar panel will actually have an output that is closer to 18 Vmp (Volts at maximum [power) when there is a load presented by the batteries. That is because batteries need a higher voltage source to accept a charge. If the charge controller supplied only the battery’s rated charge, the battery would not charge.

The inverter, the home’s meter, and the grid

The power that isn’t used to charge the batteries is sent to the inverter. An inverter converts the DC power from the solar panels or the batteries into AC power. The power drawn from the solar panels will either be consumed in the home or sent to the grid. 

If the amount of power being produced by the system is less than the amount of power the home needs, then some or all of the power produced by the system will be used in the home. The home’s meter will spin forward and the homeowner will be charged by their utility company for the power used. 

If the amount of power produced by the system exceeds the amount of power used in the home and for charging the batteries, then the excess power is sent to the grid.

A breakdown of how the system works at night

Once the sun goes down, the system may draw power from the batteries if the system is configured for it. This is often the case if the home is billed for power using Time-of-Use (TOU) billing. In California, all three major utilities charge peak TOU rates between 4 pm and 9 pm. Home batteries are sized (charge capacity) to be able to fully power the home for 6 hours. The batteries are then charged from the solar panels the next day.

The charge controller and the batteries

In the afternoon, when the power output from the solar panels declines, the charge controller will isolate the battery from the solar panels to prevent the batteries from discharging into the panels. If a float charge is desired, it will come from grid power.

Powering the home with the batteries

When desired, the charge controller will provide power to the home from the batteries. The batteries will provide continuous power up to their rated discharge level or until when they are cut off by the charge controller. To prevent over-discharging, the charge controller will cut off the batteries if they reach their maximum depth-of-discharge level. Most lithium-ion batteries will reach that level when the voltage produced by the battery’s cells drops to 3.0 V per cell. If the batteries charge is used up, the home will automatically be switched to grid power.

How the solar energy storage system works in blackouts

In a blackout, the system is isolated from the grid to prevent electrical discharge into the grid during times when the power lines may be undergoing maintenance or are damaged. During the day, the solar panels will charge the batteries. While the batteries are charging, the system’s inverter has a special circuit that allows power to be drawn from the solar panels to power selected circuits. The amount of power available is typically not enough to entirely power the home.

The amount of power available depends on the inverter

The amount of power available from a solar energy storage system depends on the type of inverter used. High-end inverters connect directly to circuits in the home that are designated to receive power during blackouts. Some lower-powered inverters simply offer outlets that you can connect an extension cord to.

How to size the batteries in a solar energy storage system

As a general rule of thumb, it’s better to have more battery capacity than you need to meet the home’s power needs. The faster you discharge batteries, the faster they wear out. If you have enough battery capacity such that regular usage only discharges the battery bank by 30 – 50% of the battery bank’s capacity, this helps ensure long battery life and gives the homeowner an emergency power reserve should they need it.

Batteries carried by Freedom Forever

Freedom Forever carries the LG Chem Cell battery. The version of the LG Chem Cell available in the US is the 9.8-kilowatt-hour RESU 10H (9.3 kilowatt-hours usable). It has a capacity of 108 amp-hours and is rated at 400 volts. Two RESU-10H batteries can be combined for a total of 19.6 kilowatt-hours. The battery is capable of outputting 5 kilowatts maximum or 3.5 kilowatts continuously.

How much battery storage capacity is needed?

To find out how long the battery will last, you’ll need to know how much power the customer needs the battery to deliver. For a grid-tied system, you can use the customer’s electric bill to estimate their power needs. If the customer needs to power their home from the battery during high peak time-of-use rates, you should estimate their needs based on their hourly power usage (if available) shown in their utility bill.

Plan for a discharge depth of 50%

Discharge depth is the amount of battery capacity that is consumed relative to the total battery capacity before that battery is recharged.  A system sized to use the batteries to 50% of their discharge depth helps ensure long battery life and provides the customer a power cushion should they need to draw extra power. For example:

Electrical usage from 4 pm to 9 pm

  • 4 PM – 5 PM = 1 kWh

  • 5 PM – 6 PM = 0.5 kWh

  • 6 PM – 7 PM = 3 kWh

  • 7 PM – 8 PM = 2 kWh

  • 8 PM – 9 PM = 1 kWh

Total demand = 7.5 kWh

Thus the ideal battery size for this example would be 15 kWh. That would leave the customer with a 7.5 kWh backup reserve. Most customers won’t use as much power as shown in the above example. Thus a single LG Chem Cell RESU 10H will provide adequate capacity in most cases.

Power available during blackouts depends on the system’s inverter

The amount of power available from the system during blackouts depends on the inverter. For the LG Chem Cell RESU 10H, there are several different inverters available. You will need to find out which circuits the homeowner wants to power during a blackout and match the inverter you’ll use in the system to their needs. 

Surge power

Appliances such as refrigerators and A/C units require a surge of power when starting up. The amount of surge power that the system can deliver in a blackout depends on the inverter. Thus you should evaluate the appliances that the customer wants to power in a blackout and choose an inverter that can deliver.

Recommended News
1. AGM vs Gel Batteries – What’s the difference?
2. Lithium, GEL, AGM battery: which type for which use?
3. How Long Do Lead Batteries Last and How To Increase Their Lifespan?
4. Understanding Solar Technology: Panels, Inverters, and Battery Storage
5. Valve Regulated Lead Acid Battery
6. Deep Cycle vs Normal Battery (Lead Acid Battery) Difference
7. 5 Battery Types Explained - Sealed, AGM, Gel
8. The Differences Between Lead-Acid, Sealed and Lithium Batteries
9. Deep Cycle Batteries -Flooded AGM Gel and Lead Carbon