Solar Panel Watt Calculation - Working Out Your Home's solar power requirements

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by: TimMcDonald | Total views: 89 | Word Count: 695

With green living becoming more and more important, many people are starting to install home solar power to supplement their power, and reduce their electric expenses.

But how much solar panel watt power do we need to say halve our power bills? And how much will that power cost us to install?

Here is a four step process that you can follow to answer these two vital questions:

1 - What Is Your Daily Power Consumption?:

To do this, get your last 12 monthly power bills and calculate your average kilowatt hour (kWh) usage per month. The reason we use 12 is because our power consumption fluctuates with the seasons. The calculation would be to add up the power used over the past 12 months and divide it by 12. But if you do not have all your power bills, then simply use last month's one.

Now take your average kwH per month and divide that by 30 to get your average kWh per day.

- So for example: If you have a monthly power consumption of 800 kWh, then your daily amount is 800/30= 26.7 kWh per day.

- So if you want to cut your bill by 50%, then the amount of solar power needed is 26.7/2 = 13.4 kWh per day.

2 - Calculate The Total Wattage Of Solar Power Needed:

To work this out you are first going to look at an insolation map to see the average usable hours of sunlight your area receives each day. A map is available on our website.

Now take the average daily kWh calculation and divide that by the number of daily usable sunlight hours, then multiply that by 1.25 (to take into account the wasted energy from wiring, charge controllers. batteries, and inverters).

- From our same example, if we lived in California where it gets on average 5.5 hours of usable sunlight per day, the solar panel watt requirements are:

13.4 kWh needed / 5.5hrs of sunlight x 1.25 = 3.045 kW or 3045 Watts a day.

This indicates that our home solar power system must have the minimum capacity to produce 3045 Watts of power.

3 - The Cost Of The Panels:

Now you you need to calculate how much these solar panels will cost you. At the moment $4.85 per Watt is the highest average cost in the United States.

- Following on from our example, the solar panels will cost 3045 x 4.85 = $14,768 to only halve our monthly power costs. This excludes the cost of wiring, charge controllers, batteries, inverters, and installation fees.

4 - Subtract Tax Rebates And Subsidies:

Before we jump the gun and think it will cost us at least $14,768 for 3045 Watts of solar panel watt power, we need to take tax incentives and rebates in account.

The new federal tax incentives and rebates recently came into affect for green energy users. What this means is you will get a considerable credit for installing solar power at home. Not to mention the additional subsidies in states like New York, California, Connecticut, and New Jersey, where the cost of your home solar power investment will be reduced further.

- Let's use our example: If we were from California we would receive tax rebates of about 20% of the cost, and a federal tax credit of 40% on the remainder. So after rebates and credits, our solar panels would cost us:

$14,768 - $14,768 x (20%) - $14,768 x (1 - 20%) x 40% = $7,089.

Just remember that this formula is basic way for you to get an idea of what home solar power will cost you. Some things could not be factored in - such as the state or country you live in, the special offers of local solar companies and the cost of the other parts (inverters, charge controllers, batteries, installation fees).

Anyway, from what you can see it would cost us around $7,089 to buy enough solar panels to halve our power bill. We, instead, either get our solar cells at cost or source them for free, and wire up our own solar panels, which obviously saved us a lot of money. The good news is, anyone can learn to find cheap solar cells and make their own solar panel watt power.

About the Author

Good news is that you can now try the Earth4Energy Guide for FREE, before deciding to make your own solar/wind power system, and slashing your electricity bill by as much as 80%. Another guide to consider getting is Efficient Planet. Click on the link to read the full review.

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