How Many Watts Of Solar Do I Need

Calculate How Many Watt Solar Panel Do I Need For Rv

To determine how much solar power an RV full of appliances requires, you must calculate the amount of wattage used daily. Doing so avoids the shortage of energy, which prevents us from even turning our lights on.

In calculating your rigs daily wattage power needs, there are two possible ways. One is by appliance use, and the other is by personally testing out your rig. These two methods are proven effective in finding out how much wattage of power your rig needs.

But first, lets learn how to convert Watts to Amp Hours.

Before starting with two methods, we should know how to convert watts to amp hours and vice versa.

Technically speaking, converting watts to amp hours and vice versa is not a 1:1 conversion. How

• Amp Hours x Volts = Watts
• Watts/Volts = Amp Hours

What Batteries Are You Using

Many people feel that the battery bank is the most critical component in any solar system. It doesnt matter how much power your solar panels generate if you have nowhere to store it for when the sun stops shining.

Lead-acid batteries have been the standard in RV electrical systems for years, thanks to their easy availability and low cost. However, they have many disadvantages like requiring frequent maintenance, being damaged if you drain them below 50% of their capacity, and they have a short lifespan, to name a few.

Lithium-ion batteries are a newer technology that offers many advantages over their lead-acid counterparts. They provide greater capacity, efficiency, and depth of discharge, both of which are critical if youre relying on your batteries and solar system as the primary source of your electrical power. Additionally, lithium batteries weigh about half of what lead-acid batteries do, require no maintenance, and usually last more than ten years.

All of these benefits come at a price. Lithium-ion batteries have a higher upfront cost, but over the battery life, they end up costing less and saving you money.

How Many Solar Panels Are Needed To Power An Average House

The average house size in the US is 2500 square feet, which should logically equate to the average energy usage of 11000kWh per year, or 30kWh per day.

However, there are variations in house size from state to state and also in solar panel power output. This is because the suns energy, or irradiance, varies by geographic location.

Read Also: Is Solar Worth It In Arizona

Alternatives To Solar Panels

As solar technology has developed more people than ever are now able to enjoy the benefits of free renewable solar energy. So, if you cant fit enough conventional solar panels to your roof, then flexible solar panels and solar roof tiles are alternative options.Flexible solar panels are a lot thinner and lighter than conventional panels which helps to make them much more flexible. This means that anyone living in a home with a roof that might not be able to support the weight of several solar panels doesnt have to rule out renewable solar energy as a way of cutting their energy bills.

Solar roof tiles, or solar shingles, tend to be more expensive than solar panels, dont generate as much energy and arent suitable for all roof types, however, theyre an aesthetically pleasing option that are popular as part of a roof replacement.

Also Check: Does Texas Have A Solar Rebate

Figuring Out How Much Solar You Need To Add To The Roof

Now that you have the Watt-hour or Kilowatt hour energy required, you can figure out how much solar you need to meet your RV power needs.

This can be a very tricky calculation to get completely accurate. Why? Because how much power solar panels actually make varies, depending on factors like location, season, weather, etc. What we will try to do, instead, is get a ballpark figure for the time of year and location you will be in.

To start, we can assume that a 100-Watt solar panel will generate on average 350 Watt hours of power per day. So if you need 1500 Watt hours, then a rough estimate would be:

1500Wh / 350Wh = 4.28W or 428 Watts of solar

The above calculation is a very rough estimate. We can get much more accurate numbers with a tool called PVWatts.

Read Also: Clip On Solar Pool Cage Lights

How Much Battery Power Required To Support Your Solar Panels

After finding out your solar power needs and stuff about solar panels, you should now figure out how much battery you should get to support your solar panels. Generally, this is dependent on the type and size of the rig that you have.

Most rigs come with a 12v battery power source. This battery power can give you 100 amp hours of electric storage, equivalent to 300 watts of solar panel energy. So if your rig has two 12v or four 6v batteries, you can have twice the storage of a regular one, and youll be able to store more energy.

Its important also to consider what type of RV you have. If you have a large RV, you may need more electric storage since youll be using up more electricity as time goes by.

How Do I Find The Right Installer

Installing solar panels is a relatively expensive, long-term decision, but when done right, it’s a home improvement project that can pay off in the long-run.

It’s important to find the right installer that can advise you on the most suitable system, and that can execute the project smoothly.

When looking for a solar panel installer, you should always get multiple quotes to ensure you are being given a fair price.

It is also a great idea to run a background check on the installer to ensure they have the right qualifications and a good track record of happy customers.

It’s a great idea to be prepared for your conversation with an installer and to help you in your research, you can follow our 6-step guide to finding the best solar panels in the video below:

If you are ready to speak to a professional installer about how many panels you need, fill in the contact form and get up to four tailored quotes from suppliers in your area. The service is free and non-binding!

Read Also: How To Make A Solar Panel From Scratch

How Many Kwh Can Your Solar Panels Produce

The amount of power your solar energy system can produce depends on how much sunlight exposure your roof receives, which in turn creates your production ratio. The amount of sunlight you get in a year depends on both where you are in the country, and what time of year it is. For instance, California has more sunny days annually than New England. But in either location, youll be able to produce enough power to cover your energy needs and say goodbye to your utility billsif you live in an area that gets less peak sunlight hours, youll just need to have a larger solar array system installed at your home. Thus, production ratios differ according to geographic location and a lower production ratio means youll need more solar panels to get the amount of energy production you need.

Why Solar System Output Can Vary From Place To Place

Solar power ratings are based on how much power they produce in ideal sunlight and temperature conditions . This is defined as the maximum power rating.

The problem is that actual sunlight conditions arent always at their peak. This means that the amount of electricity your homes solar panels will actually produce on any given day depends on several environmental factors, including:

• The average amount of sunlight your roof might get daily or annually
• Whether recurrent shading, which could be from wind-blown tree branches, obscures direct sunlight from constantly hitting your solar panels
• The size of your solar panels and the level of efficiency the solar cells operate at converting energy into electrical power

You May Like: Solar Panels On Rental Property

How Many Solar Panels Will You Need To Offset Your Electricity Usage

First I want to address most peoples motivation for going solar: I want to put on solar panels and get my electricity bill to zero!

Getting a zero dollar bill isnt as simple as installing enough solar panels to generate whatever your average daily usage is. As I explained previously, when you use electricity is almost as important as the amount of electricity you use. This is because a solar system only generates its maximum at midday on a good day.

Solar power, regardless of system size, wont do much to a massive electricity bill if its all caused by overnight air-conditioner usage!

Getting zero bills with only solar panels and no battery storage is possible. Until I added an electric car to my home, I regularly got credits on my electricity bills.

Yup my retailer was paying me for the privilege of being connected to the electricity network!

But for those of you with sky-high energy costs and not enough room for a huge solar power system, its important to focus on the amount solar energy can reduce your bills by, not whether or not it can simply get your bills to $0.

Or, to put it another way if solar power could take your $500 quarterly bill down to $50, would you be annoyed you didnt get your fabled $0 bill, or would you be jumping for joy your solar system saved you $450 in 3 months?

Now lets get into some hard numbers on system sizes with the help of my nifty solar calculator.

Example for a typical home in Sydney

Sunshine At Your Home

Your physical location is a key factor that impacts the efficiency of your home solar panels. As you might expect, solar systems are best suited for sunny areas — which is why solar is incredibly popular in states like California and Arizona. With more sunshine, each of your individual solar panels will generate more power. For our calculations, we’ll assume that you get four hours of sunshine per day.

The location of your home isn’t something that you can change, but it’s still important to recognize that your region plays a role in how well solar will work for you. In short, your panels will operate at maximum capacity when they can absorb the most possible sunlight.

You May Like: How Much Is It To Install Solar Power

V 200ah Lithium Battery

Summary

• You need around 430 watts of solar panels to charge a 12V 200Ah lead acid battery from 50% depth of discharge in 5 peak sun hours with an MPPT charge controller.
• You need around 520 watts of solar panels to charge a 12V 200Ah lead acid battery from 50% depth of discharge in 5 peak sun hours with a PWM charge controller.

Select The Product You Are Interested In:

AutoCAD-based solar design software for utility-scale ground mount solar projects.

Supported by

We wish to use cookies to better understand how you use our website. This allows us to improve your future experience on our site. In addition, cookies allow us to monitor the duration and frequency of visits to the website as well as to collect statistical information about the number of visitors to the website. Furthermore, cookies make advertising messages more relevant to you. By clicking I Agree you consent to the use of the cookies and the processing of related personal data. You can find detailed information about the use of the cookies on this website and manage your consent by clicking “Privacy Preferences”.

Recommended Reading: How Much Is The Sunflower Solar System

How Long Will A 3000w Inverter Run On Solar Power

A 3000 watt inverter either runs on or off the grid. If it is on the grid, the inverter will keep running as long as there is grid power. An off grid inverter runs as long as there is a power source available.

If your home is tied to the grid, only a power outage can stop it from running. If the solar panels cannot generate the required energy, the system will use grid power.

A 3000 watt off grid inverter can run directly off solar panels , but there are limitations. The inverter can only operate during daylight and if there is enough power to carry the load.

For example, the inverter is carrying a 2400 watt load. There are five sun hours in your area. Theoretically the inverter can run solely on the PV array for five hours.

But this assumes the array generates at least 2400 watts. If the output drops below that, the system will not be able to work properly.

Even if there is sunlight, the panels must still produce enough power to maintain the power load. This is why we recommend installing a large solar array so the system can produce more power.

These problems can also be avoided if you have a battery bank. In fact, all large off grid solar systems should have one.

How Many Solar Panels Do I Need To Power A 3000 Square Foot House

We know the average sized home requires 7924 solar watts with the average US irradiance of 5.3 peak sun hours/day, which equates to 3.17 watts per square foot.

Multiplying this number by 3000 square foot, we get 9510 watts of solar required.

9510 watts / 300 watts = 32 solar panels of 300 watts rating each

Don’t Miss: Best Solar Generators For Home Backup

Is A 4kw Solar System Worth It

With the average U.S. irradiance of 5.3kWh/m2/day , a 4kW solar system generates about 21.2kWh of energy per day, or 7738kWh/year.

This is quite a lot less than the average energy consumption for a U.S. home is 11000kWh/year. A 4Kw solar system may or may not meet a homes energy requirement, as calculating solar depends on the location and how much the home uses.

Whether such a system is worth it or not also depends on the electricity cost, which varies from state to state. The cost of the solar system must also be known, and this asset cost may be reduced by government or state solar incentives.

Solar Panel Output Per Day

Work out how much electricitymeasured in kilowatt hours your panels would produce each day by using this formula:

Size of one solar panel x 1,000

That figure x Efficiency of one solar panel

That figure x Number of sun hours in your area each day

Divide by 1,000

Read more on efficiency below.

To estimate the number of sun hours in your area, use this calculator.

Example

• Divide by 1,000:
• 1,440 ÷ 1,000 = 1.44 kWh per day

*The number of sun hours varies greatly throughout the year , and will be much lower during winter months in particular.

You May Like: How To Open A Solo 401k Account

Example Is A 4kw Solar System Worth It In Houston Texas

Calculate The Solar Payback For A 4kW Solar System In Houston, Texas

How many years to payback a 4Kw solar system in Houston?

What is the average solar payback period for a 4kW solar power system in Houston, Texas?

• City: Houston, Texas
• Solar installation cost = $10960 26% federal tax credit = $8110
• Irradiance level at Houston, Tx = 1552 Peak Sun Hours
• Power generated by solar panel system = 1552 x 4kw = 6208kWhrs
• Houston home electricity cost = 10.98 cents/kWh
• Yearly savings = solar output x electricity cost = 6208 x 10.98c = $690
• Solar payback time in Houston, Tx= solar cost/annual savings = 8110/690 = 11.75 years

The payback period might well be less than this, down to 9 or 10 years. Professional solar installers will give you accurate estimates based on their historical data, and the irradiance level in your geographic location.

Running Your Appliances Day And Night

• If you want to run just the basic RV accessories during the day , along with a few electronics plugged into your 120 volt wall sockets then you should be able to get by with 300 watts of solar panels, along with a single 12 volt battery.
• If you want to also power your RVs built-in furnace all night long, then add a second 12 volt battery, or better yet upgrade them both to two 6 volt golf cart batteries. You might still be able to get by the same 300 watts of solar, but 400 watts should cover you.
• If you want to also add a 1,000 watt microwave oven to the above, then upgrade to two 6 volt golf cart batteries, and get a minimum of 400 watts of solar.
• If you want to also add a coffee maker, Instant Pot, toaster oven, blender, food processor Then upgrade to either four 6 volt golf cart batteries, or two 100 AH lithium batteries, and get at least 600 watts of solar.
• If you want to be able to run all of the above during periods of cloudy weather, upgrade your solar panels to about 1,200 watts.

Note that the above recommendations are all minimums. When it comes to solar and battery, bigger is always better.

* These appliances normally run on propane or 120 volt power, however they still have control panels and igniters that run on battery power.

Read Also: What To Wash Solar Panels With

How Do I Check That My Solar Panels Are Working Efficiently

Your solar panels are connected to a control panel called an in-home display. This is a wireless device you can use to monitor whether your system is generating as much electricity as it should be.

If youre concerned that your solar panels are underperforming, contact the installer or manufacturer. They can send out a professional technician to investigate.

We dont recommend ever tampering with the solar panels, as this can damage the system and invalidate your warranty.