Commit to solar power
Solarwired is your solution to solar power
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV), indirectly using concentrated solar power, or a combination. Concentrated solar power systems use lensesor mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaic cells convert light into an electric current using the photovoltaic effect.
As the cost of solar electricity has fallen, the number of grid-connected solar PV systems has grown into the millions and utility-scale photovoltaic power stations with hundreds of megawatts are being built. Solar PV is rapidly becoming an inexpensive, low-carbon technology to harness renewable energy from the Sun.
Different Solar power Systems
This system design will supply the generated solar energy directly into your load. If more power is needed than the solar modules can produce, the additional power required is drawn from the utility. At night or during periods of low sunlight, the solar modules do not produce power, and the residence operates completely on utility power. This system requires grid power to ensure it fulfils its mandate. In the event of grid failure, the system will stop providing energy. This configuration is ideally suited to reduce one’s load. This load is reduced during the day in the form of a bell curve, as the sun rises in the morning and sets at night.
Standalone or Off-Grid Solar Systems are installed in situations where mains power is not available, or the client wishes to become completely independent of the grid. All power is generated by the solar panels; a battery bank stores excess power for use at night or when the sun is not shining.
The Hybrid system combines the Grid-Tie and the Off-Grid systems. This system does not require the grid to stay operational. One can program the Hybrid system to function as a Grid-Tie system, supplying the full bell curve curing the day, whilst charging a smaller battery storage bank for support in the event of grid failure at night.
Monocrystalline Solar Panels (Mono-SI)
This type of solar panels (made of monocrystalline silicon) is the purest one. You can easily recognise them from the uniform dark look and the rounded edges. The silicon’s high purity causes this type of solar panel has one of the highest efficiency rates, with the newest ones reaching above 20%.
Monocrystalline panels have a high power output, occupy less space, and last the longest. Of course, that also means they are the most expensive of the bunch. Another advantage to consider is that they tend to be slightly less affected by high temperatures compared to polycrystalline panels.
Polycrystalline Solar Panels (Poly-SI)
You can quickly distinguish these panels because this type of solar panels has squares, its angles are not cut, and it has a blue, speckled look. They are made by melting raw silicon, which is a faster and cheaperprocess than that used for monocrystalline panels.
This leads to a lower final price but also lower efficiency (around 15%), lower space efficiency, and a shorter lifespan since they are affected by hot temperatures to a greater degree. However, the differences between mono- and polycrystalline types of solar panels are not so significant and the choice will strongly depend on your specific situation. The first option offers a slightly higher space efficiency at a slightly higher price but power outputs are basically the same.
What Are Solar Batteries
The whole idea of a battery is to store energy to use on demand , the concept is exactly the same when dealing with Solar Power but there are some fundamental differences between the typical battery we use every day to a Solar Battery .
For Solar Power we need to:
- Charge the battery during the day using the sun
- Use power from the battery during the evening when there is no sun
- Then recharge again the next day, repeating the process over and over again
You will hear the term “Deep-Cycle”, what this refers to is the Depth Of Discharge . Deep-Cycle Solar Batteries are specifically designed to regularly discharge until it has used most of its capacity .
The depth of discharge will depend on the type of battery you choose (we will go into this more in-depth below).
A typical Lead-Acid option you will go to 50% DOD (Depth Of Charge) . Whereas with the Lithium-ion Solar Batteries you will go to 80% , this is important to understand when calculating your solar battery needs.
Sealed Lead Acid
An upgrade to the flooded version, Sealed Lead Acid eliminates the maintenance required compared to its counter partner.
It’s not without its drawbacks, however, a shorter lifespan (depending on the brand) and higher price they can make a difference if you require a large amount of storage.
How does it work?
AGM (Absorbent Glass Mat) are capable of handling higher temperatures with a lower self-discharge when they are idle. The cells have a lower resistance compared to conventional cells, they don’t leak and they don’t need to be in an upright position.
- Completely sealed so the risk of acid leaks
- No maintenance is required
- Don’t have to be mounted upright
- Charge quicker with a lower voltage
- Lifespan from around 3-5 years (depending on brand)
- More expensive
- If it’s discharged more than 50% life expectancy will go down
The most efficient battery on the market Lithium-iontechnology is the future of solar storage for solar power systems. They waste significantly less power when charging and discharging. The cycle is deeper using more of their capacity with a long lifespan.
Completely maintenance free they are lighter, smaller and they don’t produce as much heat as other Lead Acid batteries which are perfect for setups that have space restrictions.
- Maintenance free
- Lighter and smaller
- Don’t have to be mounted upright
- Produce more cycles (5000 – 7000)
- Can produce 100% of the stored energy
- Lifespan from around 10-20 years
- High charging and discharging efficiency, more than 95%
- Highest cost
How Many Batteries Do You Need For A Solar System
Working out how many batteries isn’t as difficult as you might think.
Here’s what you need to do:
Start with looking at your electricity bills
Take the last 12 months and add the kWh together
Divide the total kWh by 12 to get your daily average
From that average, figure out what portion you use during day and night
Night time usage is required to be cycled through the use of batteries
Say it is 3kwh required for night and you wish to use lead-acid batteries, using the formula:
watts = volts x amps this is what the equation will look like:
3000 watts = 12 volts / (?) Amps 3000 / 12 = 250 Amps
Now because with lead acid you can only use 50% of the battery to not damage it, you would have double the amps to have 5000 watts of available power.
Therefore: 12v 833.33 Amps gives you 5000w of usable power .
Changing the voltage of the battery bank:
If you were to use a 24-volt battery bank (2 x 12v in series) you would require a 24 volt 416 Amp battery bank, and so on. This is where you choose the required battery for your needs.
You commonly get 100A or 200A batteries , so you would require 4 x 12v 200A batteries to get a 24v 400A battery bank (2 in series and 2 in parallel).
For a 48v bank, would be 4 in series, so 48v 200A bank .
All of these give the same amount of usable power, just configured differently.
Sizing Your Battery Bank
Depending on which battery type you will be using you will need to do some further math to work out the actual amount, this is because the batteries are not 100% what they output, there are variables which affect the overall result.
Note: Be aware that you need to double up for Lead Acid batteries .
HERE IS AN EXAMPLE OF SIZING A LEAD ACID BATTERY:
10kWh x 2(for 50% depth of discharge) x 1.2(inefficiency factor) = 24 kWh
HERE IS AN EXAMPLE OF SIZING A LITHIUM BATTERY:
10kWh x 1.2(for 80% depth of discharge) x 1.05(inefficiency factor) = 12.6 kWh