Do you want to design your own off-grid solar system? Here are the first six steps to help you get started.
#1) Figure out how much power you need
Planning a solar system without knowing how much power you’ll need is like to planning a road trip without knowing how far you’ll be going or what vehicle you’ll be driving. Now go get some gas for the trip. How much is it? That, of course, is dependent on your distance and gas mileage. Solar is the same way. You can’t just say, “I’m going to get two solar panels and a battery,” and expect it to suffice. Enter what you’ll be powering with your solar power system into our load calculator. You must remember everything that will be powered by your system – even seemingly minor adjustments might have a significant impact.
#2 Calculate the amount of batteries you need
After you’ve determined how much power you’ll need, you’ll need to determine how many batteries you’ll need to store it.
- Do you only need enough batteries to last a day or two, or do you need enough to last three or four days, or perhaps longer?
- Do you have a backup power source, such as a generator or turbine, in case the sun goes out?
- Will the batteries be kept in a warm room or will they be kept in a cold place?
Batteries are designed to be stored at a temperature of roughly 80 degrees Fahrenheit. The larger the battery bank you require for sub freezing temperatures, the colder the space. The size and cost of your battery bank are influenced by each of these factors.
Which battery bank voltage do you require: 12V, 24V, or 48V? To keep the number of parallel strings to a minimum and limit the amount of current flowing between the battery bank and the inverter, higher voltage battery banks are employed in bigger systems. A basic 12V battery bank makes sense if you only have a small system and want to be able to charge your phone and run 12V DC gadgets in your RV. However, if you need to power more than 2000 watts at a time, 24 volt and 48 volt systems should be considered. It will also allow you to use thinner and less expensive copper wiring between the batteries and the inverter, decreasing the number of parallel strings of batteries.
Based on these answers, use our off-grid calculator to figure out what big battery bank you’ll need.
#3 Calculate the number of solar panels needed for your location and time of year
Our off-grid calculator’s second half can assist you in determining how many solar panels you’ll require for your solar system. After you’ve calculated how much energy you’ll need per day using the load calculator, you’ll need to tell it how much sunlight you’ll be able to harvest. The term “solar energy” refers to the amount of energy that is accessible from the sun at a given place “The hours of the sun.”
The total number of “The number of hours the sun shines at an angle on your solar panels throughout the day equals sunlight, as if it were shining straight on them when they generate the greatest power. Because the light isn’t as bright at 8 a.m. as it is at noon, an hour of morning sun can be considered as half an hour, but an hour from midday to 1 p.m. can be treated as a full hour. And, unless you live near the equator, the number of hours of sunlight in the winter is not the same as in the summer.
You should use the technique in the worst-case scenario for your locality, which is the season with the least quantity of sunshine. As a result, you won’t be short on solar energy for a portion of the year. You don’t need to plan for winter if it’s a summer camp, but if it’s a year-round home or a hunting cabin, you’ll need to tell it how many solar hours correlate to winter.
#4 Select a solar charge controller
So, now that we have batteries and solar, we need to figure out how to get the solar electricity into the batteries. Take the watts from the solar and split it by the battery bank voltage for a very rough estimate of what big solar charge controller you’ll need. To account for a safety factor, add extra 25%.
There’s a little more to think about now when choosing a charging controller. PWM and MPPT are the two main types of technologies used in charge controllers. In summary, a PWM charge controller can be used if the voltage of the solar panel array matches the voltage of the battery bank. PWM can be used if you have a 12V panel and a 12V battery bank. If the voltage of your solar panels differs from the voltage of your battery bank and you can’t link them in series to make them match, you’ll need to utilize an MPPT charge controller. If your solar panel is 20 volts and your battery bank is 12 volts, you’ll need an MPPT charge controller.
#5 Select an inverter
We need to make the power useful now that the batteries have been charged efficiently. You can skip this step if you’re simply using your battery bank to power DC loads. However, if you’re running any AC appliances, you’ll need to convert the direct current from the batteries to alternating current. It’s critical to understand what kind of AC power you’ll require. In North America, the standard voltage is 120/240V split phase, 60Hz. It is 230V single 50Hz in Europe, much of Africa, and a few nations in South America. It’s an interesting blend of both on certain islands. Some inverters can be adjusted for voltages and/or frequencies, while others are fixed. So make sure the specifications of the inverter you’re interested in match your requirements.
If you have the North American standard, you must determine whether you have any 240V appliances or if they are exclusively 120V. Some inverters can output 240V, and the output can be wired to use either 120V or 240V. Other inverters can be stacked, with each one producing 120V but generating 240V when coupled together or stacked. Others can only output 120V and cannot be stacked. To select which inverter is suitable for you, read the specifications once more.
You’ll also need to know how many watts your inverter can handle in total. Fortunately, you developed a loads list in step one that calculated both the constant watts and surge requirements of your loads. Please keep in mind that an inverter is built for a specific voltage battery bank, such as 12, 24, or 48 volts, thus you must first determine what voltage battery bank you will have before purchasing an inverter. If you plan on expanding your system in the future, keep this in mind. If you decide to upgrade to a higher voltage battery bank later, keep in mind that the lower voltage inverter will not work in the new larger system. So either plan ahead and start with the greater voltage, or expect to replace your inverter in the near future.
#6 Balance of system
Okay, we’re cheating a little by combining everything else into one final step for system balance, but there are a lot of other small components that are required, including:
After you’ve completed these six steps, you’ll be well on your way to building your own off-grid solar system.
How do you calculate the size of a solar power system?
Examine previous utility bills to establish your home’s usual energy usage. You may figure out how many solar panels you’ll need by calculating your household’s hourly energy demand by your area’s peak sunlight hours and dividing by the wattage of each panel. To demonstrate a range, use a low-wattage (150 W) and a high-wattage (370 W) example (ex: 17-42 panels to create 11,000 kWh/year). It’s important to keep in mind that the size of your roof and the amount of sunshine it receives are both important considerations.
All of these calculations will be handled for you if you engage with a professional solar contractor. Look no further if you’re looking for a calculator to figure out “how many solar panels do I need?” SunPower Design Studio can help you calculate the size of your system, monthly savings, and the aesthetics of a solar array on your own roof. This interactive tool generates a solar estimate in seconds and may be used on your own or over the phone with a SunPower representative (800) 786-7693.
What is the definition of solar PV system design?
Solar photovoltaic modules create power, but they are only one of several components in a comprehensive photovoltaic (PV) system. A number of different technologies must be in place before the generated electricity may be used in a home or company.
Mounting Structures
PV arrays must be supported by a robust, long-lasting framework that can endure wind, rain, hail, and corrosion for decades. The PV array is tilted at a fixed angle defined by the local latitude, structural orientation, and electrical load needs. Modules in the northern hemisphere are aimed due south and slanted at an inclination equivalent to the local latitude to get the highest annual energy output. Rack mounting has been the most popular approach due to its durability, versatility, and ease of construction and installation. Methods that are more complex and less expensive are still being developed.
Tracking mechanisms mechanically move panels on ground-mounted PV arrays to follow the sun across the sky, resulting in more energy and higher returns on investment. One-axis trackers are usually made to follow the sun from east to west. Modules with two-axis trackers can remain oriented directly at the sun throughout the day. Tracking, by definition, entails higher upfront expenses, and advanced systems are both more expensive and require more upkeep. The cost-benefit analysis for ground-mounted systems is increasingly favoring tracking as systems develop.
How can I figure out how many solar panels I’ll require?
It’s crucial to consider the size of your property when calculating how many solar panels you’ll need. To fully offset their electricity demand, the average homeowner would require 28 to 34 solar panels. Based on the size of your home, the chart below provides an estimate of how many panels you could require.
Divide the size of your solar system by the wattage of each panel to get the number of panels you’ll need (which averages around 320 watts).
If you want a 4 kW system, for example, divide 4 kW (or 4,000 watts) by 320 watts to get 12.5. Round up to 13, which is the number of panels you’ll require.
You can also figure out how many panels you’ll need for each appliance separately. This method is advantageous if you need to add panels due to increased usage or while purchasing a new appliance.
Divide the appliance’s average annual wattage by the panel wattage to arrive at this figure. A 600 kWh refrigerator, for example, would require two solar panels (600 / 320).
How much kW of solar power do I require?
So, how many solar panels do you need to power a home based on these factors? You’ll need to figure out two things to estimate how many solar panels you’ll need without a professional assessment: how much energy you use and how much electricity your panels will produce.
Calculating How Many Kilowatt-Hours Your Home Uses
The average American home uses 10,649 kWh of energy per year, according to the latest figures from the US Energy Information Administration (EIA). This, however, differs from state to state. Consider the following scenario:
Add up the kWh indicated on your last 12 power bills to get a better idea of how much energy you consume annually. The size of your home, the number of occupants, your electricity usage patterns, and the energy efficiency rating of your home gadgets will all influence these figures.
Solar Panel Specific Yield
After you’ve calculated how many kWh your home needs annually, you’ll need to calculate how many kWh each of your solar panels produces over the course of a year. This will vary depending on the type of solar panel used, the roof’s characteristics, and the location’s peak sunlight hours.
In the solar power industry, a common metric used to estimate system capacity is “specific yield or “specific production. This is the annual kWh of energy produced for each kilowatt of installed solar capacity. The amount of sunshine accessible in your location has a big impact on your yield.
Check credible sources like the World Bank solar maps or the National Renewable Energy Laboratory’s solar radiation database to obtain a better sense of the specific yield that can be attained in your location. Divide your annual kWh usage by the specific yield per kilowatt of solar capacity to find how many kW are required to power a home.
For example, if your home uses 15,000 kWh of energy per year and solar panels in your area produce 1,500 kWh/kWp, you’ll need a system with a capacity of roughly 10 kilowatts. Paradise Energy Solutions has also devised a general formula for estimating the size of solar panel system you’ll require.
Simply multiply your annual kWh by 1,200 to get the required solar capacity in kilowatts. So, if your total energy consumption during the last 12 months is 24,000 kWh, you’ll require a 20 kW system (24,000 / 1,200 = 20).
What are the three different kinds of solar panels?
The efficiency of all PV panels varies. That is, certain types and even brands of solar panels are more effective than others at converting sunlight into power. This is due to the fact that the amount and type of silicon cells in a panel might vary. A Solar Panel’s cost, size, and weight are often determined by the number of cells it contains. Although it is commonly assumed that the more silicon cells in a panel, the higher the wattage and power output, this is not necessarily the case. The quality and efficiency of the solar cells themselves determine the panel’s power output.
We’ll look at the three primary varieties of solar panel cells in this blog: polycrystalline, monocrystalline, and thin-film. The first step in choosing the right panel for your home, business, or community is to understand the differences between the three.
What are the steps for designing and installing a solar photovoltaic system?
To calculate the total Watt-hours per day required from the PV modules, multiply the total Watt-hours per day required by 3.43.
the total peak-wattage required for the PV panels to power the appliances
Subtract the answer from item 2.1 from the rated output Watt-peak of the PV modules that are available.
Greetings. Any fractional part of the result should be multiplied by the next largest whole number, which will be the result.
How does solar energy become calculated?
To estimate the electricity generated in output of a solar system, a formula E = A x r x H x PR is used globally. For example, the solar panel yield of a 250 Wp PV module with a 1.6 m2 area is 15.6 percent.
How much electricity is generated by a single solar panel?
What is the average amount of energy produced by solar panels each hour? Depending on the geography and weather circumstances, the average solar panel produces between 170 and 350 watts per hour. This equates to approximately 0.17 to 0.35 kWh per solar panel.
What is the formula for calculating the panel generation factor?
When estimating the size of solar photovoltaic cells, the panel generation factor (PGF) is utilized. It is a variable factor that is affected by the climate of the site (depending upon global geographic location).
For example, it is 3.43 in Thailand, 2.93 in EU countries, and so on. When designing the size of solar photovoltaic cells, this factor is used to calculate the “Total Watt-Peak Rating.”
As a result, “Total Watt-Peak Rating” equals “Total Watt-hours per day required/generated from PV modules” divided by “PGF.” “Total Watt-Hours per Day” equals “Total Watt-Hours per Day Required by Appliances.” “1.3 times” multiplied (the energy lost in the system). Simply divide the above obtained “Total Watt-Peak Rating” by “Watt-Peak of each cell OR Watt-Peak of each square meter size,” whichever is more convenient, to determine “size of PV cells” OR “number of PV cells.”