Can you imagine a day and a half without electrical power. In our rural community there are a lot of small business owners, shop keepers, yam and poultry farmers who depend on energy for their business operation. Regardless, electricity has been gone for more than 30 hours. A rural solar system will be able to provide reliable energy supply to homes and small businesses. The video below shows how the rural solar system works.
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TeamKB, It is a beautiful day here in Trelawny, Jamaica and if anybody knows anything about rural Trelawny on a Sunday evening is that a lot of music plays in the community. Sunday is the day for church music and some great Oldies but Goodies. Unfortunately, at this moment the place is just dead silent, you can feel the silence. There has been a power outage since yesterday.
My parents are both farmers. We are involved in a variety of farming practices including the most popular crop in rural Trelawny: yellow yam. Besides yam production my parents also rears pigs and chicken and those are their primary source of income. Electrical power is a critical component of our small business operation to keep our chicken and pork meat frozen and avoid spoilage. To mitigate against the frequent power outages we have installed a small rural solar. This renewable energy system allows us to power our two deep freeze refrigerators and lights for the baby chicks in our coup.
Wind or Solar which is better?
We started our renewable energy system with one wind turbine and a few batteries a couple years ago. We recently added a 6 solar panels. Our wind turbine is rated at 1000W. A single wind turbine can produce more power than 10 solar panels combined. This calculation will show you how is that possible. In Trelawny wind blows at night and day unlike solar which has a maximum yield of about 5 hours per day vs 24 hour access to wind energy.
Therefore ten panels, rated at 250W, producing for five hours per day for thirty days in the month = 10 x 250 x 5 x 30 = 375 kWh. In Trelawny my wind turbine produces about 60% of the time. Therefore I can calculate the amount of energy I can get from the wind turbine. One wind turbine rated at 1000W, at 60% efficiency, operating for 24 hours per day for thirty days = 1000 x 0.6 x 24 x 30 = 432 kWh. Therefore the calculation shows that 10 solar panels produce 375kWh in 30 days. While the wind turbine produces 432kWh per month.
How much energy can the wind turbine supply
Let us consider one of our deep freezers that consumes 1600W when it starts for the first few seconds yet operates at 100W daily. The refrigerator operates around the clock for 24 hours per day and 7 days per week. We can therefore calculate how much energy it consumes for the month by multiplying the power by the amount of time it is in operation. Power used = 100W x 24 x 30 = 72,000Wh or 72 kWh.
The rural wind turbine that generates 432 kWh in a given month can power (432 / 72 = 6 refrigerators in a given month). Wind does not blow constantly every day and some days are cloudy which result in inefficient solar panels. To avoid power outages you will be required to have a few batteries to store some of the energy for night time usage.
Understanding solar batteries
For our rural solar system we have 4 Trace batteries rated at 115AH. The Amp Hour or AH rating of your battery is an indication of its charging capacity. This indication is similar to a car in the parking lot rated at 42 mpg (miles per gallon). This may be interpreted literally as if you pour 1 gallon of gas in the car it should be able to drive for 42 miles. This is true only if you drive at a moderate 25 miles per hour. Consider seriously stepping into the gas and speed off at a whopping 100 mph that car will likely run out of gas before reaching the 1st milestone.
OK TeamKB, enough about cars and gas and mileage lets equate this to batteries by saying the faster you take the energy from your battery the lower the Amp Hours. And No, I do not mean the faster you use the power stored the faster it finishes. But the faster you use power, the less power you will have to use. Deep cycle solar energy batteries are rated for 20 hour usage. Therefore my 115AH batteries will give me about 5.75AH of power each hour for 20 hours. If I try to use all the power in one hour instead of the full 115AH I will only have about 80AH instead.
How many batteries do you need
I hope your head does not hurt from all those battery statistics for our rural solar system. We have 4 Trace 6 volts batteries rated at 115AH which are the cheapest and possibly least efficient batteries on the market. Our system is a small 12V system. To get our four batteries to produce at 12 volts we create 2 battery banks. We connect the first two of four batteries in series 6V + 6V = 12V and that is our first bank. This is also done with the second pair of batteries for the second bank. Finally we connect the 12V in parallel with 12V or both banks in parallel. Connecting in parallel keeps the voltage constant and doubles the AH. In our case the four batteries can be considered as a single large 12V battery rated at 230AH.
If I want to find out if this 12V battery can power my deep freezer for the entire night from 6am to 6pm. Simply divide the Amp hour (230AH) by the number of hours (12 hours) and then multiply the solution by the voltage of your battery bank (12Volts). The solution must be greater than the operating voltage of the refrigerator which in our case is 100W. Power = 230AH / 12hours = 19.17 x 12 Volts = 230W each hour. Therefore this battery bank can provide us with 230W of power, every hour for 12 hours. This doubles the amount of energy our refrigerator will need for each hour during the night. Which means that we can add a few LED light bulbs, a television and a laptop to account for the extra 130W of power available.
How much will you need to spend for a rural solar system
The cost for a renewable energy system unfortunately is not black or white. Prices are based primarily on a customers monthly energy consumption and type of appliances used. Nonetheless A J$300,000 or U$3,000 can acquire a simple renewable energy system design. Especially relevant, you will be able to purchase the items below for a simple system set up.
4 Solar Panels rated at 250W = $80,000
Solar Mounting and Connector + Wire = $20,000
4 Trace Batteries 6 Volts rated at 115AH = $48,000
1 Xantrex C60 charge controller + display = $35,000
1 Inverter rated at 1500W =$70,000
DC Breaker and Battery wire + Miscellaneous =$47,000
Total =J$300,000 or U$3,000
This off grid rural solar system will generate 1000W of power daily and stores 2.76 kWh of power for overnight usage as a result of the battery capacity.
What can this power | What this will NOT be able to power
Small standard refrigerator | Washing machine
LED Lights and Laptop | Air Conditioning Unit
Television set, radio, iron | Large Microwave
You may also be interested in: Off Grid Solar System
To power the items in RED you will need an inverter larger than 4,000W in addition to more batteries. Consequently the beauty of these small systems is the flexibility to upgrade from a 1.5kW to a 4kW. Customer pays the difference in price plus installation and electronics and we’ll change the units. Please feel free to give us a call +1876-834-5971 for a custom system price. Hence Let us help you stop paying monthly energy bills.
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In conclusion Start Small, start today. Renewable Is RELIABLE! This is #TeamKB, Let us #KeepBelieving