What Can I Power with a 150 Watt Solar Panel?

A 150 watt solar panel is an ideal choice for camping, RVs and small homes. It isn’t as costly as largo panels but offers plenty of power. But exactly how much power can you expect? Will it be enough for your appliances and other electronics? That is what we will find out in this guide.

A 150 watt solar panel can run several light bulbs, fan, laptop, TV, radio and movie player. However the solar panel cannot run a refrigerator, microwave, sump pump and other large appliances.

How Much Power Can a 150 Watt Solar Panel Produce?

The answer seems simple, right? A 150 watt solar panel will produce 150 watts an hour or 750 watts a day with 5 sunlight hours (150 x 5 = 750). With more sun hours, more watts. However it isn’t that clear cut.

150 watts is the peak output for a 150W solar panel. It is the maximum power the module can produce when the sun is high above the horizon. As the sun goes down, so does the solar panel output.

The sun is at its highest around 11 AM to 12 noon, so expect output to be close to or at 150 watts. As the sun goes down, power generation may drop from 150 to 100 watts or so.

The later the afternoon gets, the faster the power drop. Also note that 150W solar panels may produce only 80W or so in the morning, gaining slowly as the day goes on. Of course this can be altered in case of a sudden downpour.

Instead of 150 watts an hour, expect 130W to 140W on a good day. And instead of 750 watts a day, it is more like 600 to 700 watts. Can you get more than this? Yes, but it is better to be conservative with your estimates.

One way to get maximum output is to buy a high quality PV module. The Rich Solar 150W Monocrystalline Solar Panel for instance, has been optimized to give you 150 watts under ideal weather.

What is Solar Panel Efficiency?

Not all 150W solar panels are made equal, and efficiency is one of the biggest difference makers. The more efficient the panel, the higher the output regardless of the weather.

Solar panel efficiency determines how much sun energy the cells turn into electricity. An efficiency rating of 20% and above is recommended for 150W solar panels. This ensures the cells are optimized to convert as much sun energy as possible into direct current.

Do not let the 21% efficiency mislead you. That is a solid number for solar panels, and that is enough for most solar power users. If you have a large solar array with that efficiency rating, it can power a lot of appliances.

The higher the efficiency, the more energy is converted into electricity. The good news is solar technology is improving constantly so efficiency ratings re always getting better.

What Appliances Can You Run on a 150 Watt Solar Panel?

First you have to calculate how many watts a 150W solar panel produces in a day. Next you figure out how many watts your appliances consume. Note that this is only for one day and does not include batteries.

Examples:

• You can run a 250W laptop for 2 hours
• Run a whole house fan for an hour
• Run a CD player for approximately 14 hours
• Watch TV for 3 to 4 hours depending on its watt consumption

if a 150W solar panel produces 660 to 700 watts a day, you can use it the following way.

• 700 watts for 1 hour
• 350 watts for 2 hours
• 250 watts for 3 hours
• 175 watts for 4 hours
• 140 watts for 5 hours

You can also use any number of appliances as long as the total watts is 700 watts or whatever your solar panel has produced. Or you could use several light bulbs and turn on the fan while using your laptop or watching TV for instance.

You can connect several 150W solar panels to increase amps or voltage. Connect the solar panels in parallel and you get an amp boost. If you want to increase the voltage, connect them in a series instead.

You get a parallel connection by connecting the solar panels’ positive terminals together and doing the same with the negative terminals. To join solar panels in a series, connect their positive and negative terminals.

If you connect your solar panel to a battery bank, your usage options increase as well as the number of hours you can run appliances. As good as solar panels are, they get better when paired with a battery.

What is the Best Battery For a 150 Watt Solar Panel?

You can use any type of battery as long as it is compatible with the solar panel. Most 150W panels are 12V, so any 12V battery will do. The only question is what battery size to use.

The right battery size for a 150W solar panel depends on how many appliances you will use and for how long. It also depends on the battery discharge rate, as that limits how much of the capacity you can actually use.

if you consume 600 watts from your solar panel for the five hours it runs in sunlight, and you need another 600 watts when the sun goes down, you need a 60ah to 70ah lithium battery or a 100ah watt lead acid battery. Here’s why.

First we have to convert watts into amps, as that is how battery size is measured.

Watts / volts = amps
600 watts / 12 volts = 50 amp hours

Lithium batteries have a discharge rate of 70% to 90%, so you can use nearly all of it. If 50 amps is 600 watts, you get 500 watts or so from a lithium battery with a 90% discharge rate. So a 60ah or 70ah battery should be enough to give you the power you need.

With lead acid batteries the discharge rate is fifty percent. You must get 100ah so you can use 50ah and can still charge at the recommended rate. You can use these same calculations regardless of how many watts you consume with your solar panels. The more watts you need, the larger the battery.

Our suggestion is to get a 100ah lithium battery so you can get maximum use per charge. A good option is the ExpertPower 12V 100ah LiFePO4 battery as it is very dependable and can run under different solar system configurations.

Are Solar Batteries Necessary to Use a 150 Watt Solar Panel?

You can run DC powered devices off the solar panel. For AC powered electronics, you have to use an inverter to operate them, so you don’t really need a battery, but it makes things easier if you do.

Without a battery you are completely dependent on the sun. If the weather takes a turn for the worse, the power supply cold get cut off. Sudden loss of power is not good for appliances, so having a consistent energy source like a battery is safer.

If you are on a grid tied system you don’t need a battery. You are hooked up to the power company and can use their energy supply in case the solar panel cannot produce the required output. However for off the grid setups, you cannot do without a battery bank.

5 Factors That Determine Solar Panel Output

In a perfect world you might get close to 750 watts, but in reality the condition is almost never ideal. The following are the most important elements that determine solar panel production, of any size.

Weather

The higher the sun is in the sky, the better for solar panels. The panels convert the sun’s energy into electricity, not the heat. High temperatures will not improve performance, in fact it could hamper solar production as the cells might overheat.

The number of sunlight hours available is important obviously. Even if heat is not essential, the sun must be out there striking the solar panels. If it is overcast, raining or snowing, production will slow or stop completely.

Location

Even if the weather is clear, a lot depends on your location. Some areas in the United States just receive more sunlight than others and that affects solar output.

Suppose it is summer in the US, and you have two 150W solar panels. One is in Seattle and the other is in Texas. Both panels have the same specs but the one in Texas is going to produce more watts per day compared to the one in Seattle because of the climate.

Solar Cell Damage

Solar panels are sturdily built, but nothing is perfect and damage can occur. Sometimes there are manufacturer defects you need to watch out for as well.

Among the most common issues are glass cracks, hot spots, poor solar cell connection or just the panel wearing out due to old age. If your system is showing signs of damage or wear and tear, check your solar panel warranty if you can still have it repaired.

Solar Panel Shading

Whether you are using a rigid or flexible solar panel, shading or blocking must be avoided. It has a huge impact on solar panel output no matter the size or number.

You can have a large solar array directly pointed south, but if there are leaves or debris blocking the cells, production will drop. How much it goes down depends on the severity, but you won’t get the maximum possible output if the solar cells are shaded. Fortunately, cleaning solar panels can solve this issue easily.

Conclusion

Although 250 and 300 watt solar panels have become the standard size for homes and off the grid systems, a 150W solar panel is still a good option if you want something lighter and more affordable. As shown here you can actually power a lot of appliances with 150W, especially when paired with a battery.