Can Solar Panels Power a House? • SOLAR POWER SECRETS (2024)

What Can Solar Panels Power in My Home?

Whether a solar electric system can entirely replace the utility grid and meet your daily energy needs depends on your daily consumption.

If your home is already connected to the utility grid, replacing completely the utility with a PV system might NOT be cost-effective.

Offsetting a part of your electrical bills through a solar system, however, could be the best way to save money on electricity.

While you take your connection to the local utility grid for granted, solar-produced electricity is more expensive because your costs for solar electricity production are higher than the costs of your utility grid for producing electricity.

Therefore before implementing a solar electric system, you should try to reduce your daily electrical consumption. You should start with increasing the energy efficiency of your home or office. Achieving energy efficiency means reducing electrical consumption and your monthly electricity bills respectively.

Yes, saving energy is less expensive than producing energy. By improving energy efficiency the cost of the photovoltaic system you are going to install will be reduced.

Electrical heating appliances (dishwashers, washing machines, electrical boilers, tumble driers) are not recommended to be powered by photovoltaic systems.

For each heating appliance, you should find a proper both energy-efficient and cost-effective alternative. As a matter of fact, heat is always an expensive source.

Actually, you could power all those devices by solar electricity. You will rarely see anyone do that however since heating devices are known as ‘power-hungry’. This means that powering heating devices by photovoltaics turns out to be very expensive.

Calculating your daily consumption

Calculating your daily electricity consumption is a step toward both reaching energy efficiency and implementing a solar electric system.

Since an off-grid is not connected to the grid, it is irrelevant to talk about offsetting a part of your energy consumption to the PV system. The PV system should be able to meet all of your daily energy needs.

Calculating your daily electrical consumption means performing a load analysis – determining your daily electrical energy consumption in Wh (or kWh).

Performing a load analysis is very important since your PV system should be neither oversized (=waste of time and money) nor undersized (=useless for you).

To calculate your total average daily load you need to determine the amount of energy (in kWh) consumed by each AC load. Therefore you need to know the rated power of each load, the amount of time it is used each day and the number of days this device is used each week.

You can find the power rating of each device on its label. If only current (in Amps) is stated, multiply it by the voltage to get the power consumed. You get the energy needed for every device by multiplying the power by the number of hours the device is on.

A hybrid solar power system is a combination of photovoltaic generator and alternative power generator operating by wind or fuel. Such a generator charges the batteries upon lack of sunlight and is used either as a backup or in case the PV system alone cannot meet specific energy demands.

Here is a simplified view of a hybrid system:

Here are the advantages of a hybrid system:

• Electricity is available at an acceptable cost during long periods of cloudy/rainy weather or in winter
• You can power some of the power-hungry devices (not all, however!) in your house
• You could buy smaller (less expensive) battery bank and inverter

What about the disadvantages of a hybrid system:

• Additional costs required for fuel and maintenance
• Higher costs for buying fuel generator and bigger battery charger

So, when you should buy a hybrid system rather than a purely solar electric one:

• When the sun is not enough during some months of the year, so a PV system cannot cope alone with your energy needs
• When you want to lower your initial costs
• When the access to your house is difficult and/or expensive
• When maintenance costs are not a problem
• When you demand that electricity must be available all the time

Click here to discover how to get more details about hybrid systems.

So, if you live away enough from a utility grid, and you consider buying a stand-alone PV system, first of all, you should answer the following questions:

• What applications do I need to power?

Above all, you should mind that a PV system is not economically beneficial to be used for powering heating appliances. Therefore you should find a good alternative solution for heating, cooking, and refrigeration.

• Have I already made your building energy-efficient? Are my loads as efficient as possible?
• Do I live in my house during all the year, or just during certain seasons?

If you live in your building in winter and your energy consumption is as much as in summer, a more cost-effective solution would be a hybrid system.

It will reduce your initial costs on batteries and, most probably, PV modules.

You may find the answer to the important question “How much solar power do I need” by reading this article: “How many solar panels do I need”