100% Solar-Powered House: a Realistic Goal or an Unattainable Dream

 

Living in a 100% solar-powered house is a dream for many people who care for nature and aim to have a green lifestyle. Is it a realistic goal or an unattainable dream? In fact, this is a real possibility, and today there are many houses that run on solar power alone. It is certainly possible for a residential solar power system to collect and store enough solar energy to power an entire household. Even if you have a large house, there is a possibility to switch completely to solar energy using batteries.  A solar power system and solar thermal system (or PVT photovoltaic thermal hybrid) can provide solar electricity, hot water, heating, and cooling so, you can run your house solely on solar energy throughout the whole year. Of course, going solar entirely is not as easy as it seems, and it is definitely not cheap. Also, you have to consider some basic things before going off-grid. And you have to be very precise during the planning.

First, you should determine your energy needs – how much energy your house typically uses. You may see your previous electricity bills, as well as, calculate your electricity needs using online calculators. Also, important factors are the size of your house, how many people live there, the roof’s surface, what direction the roof faces, trees around that may shade, your location, and peak sunlight hours. You may take a look at meteorological data for your area, too. This information will help you plan a solar panel system that will make enough electricity. Concerning the weather forecast, you should be prepared for the worst scenario.

Solar energy is free, but to convert this energy to electricity, you will need equipment that is expensive, especially if you want to power your entire house. You will need a solid initial investment before reaching the moment when you and your family will enjoy free and clean electricity. But think of it as a long-term investment. Although to use solar energy you will need the equipment and installing that equipment, which comes at a high price, solar energy is now among the least expensive forms of renewable energy. And if you care for the environment and want to have a green lifestyle, going solar is the right step.

There are also energy-related incentives and rebates that will help you reduce the cost of your solar power system. Keep in mind that the benefits vary in different countries and different states that’s why you have to check them carefully. Taking advantage of grants, tax credits, and per-watt rebates might make the initial investment more affordable for you.

To power your entire home with solar energy you will need to buy more solar panels. But the number of solar panels is not all that matters. Their quality, panel output, and efficiency are important, as well. Most residential solar panels have between 16%-20% efficiency (22% are the best). If you can afford to buy more efficient solar panels, then you would need less space. It is essential to find a good solar installation company that will help you choose the best solar panels for your home and design, and install your solar panel system. It is great to do your own research and have as much information as you can gather before going solar, but professional help and advice are absolutely needed. 

In general, the average home in the United States uses 10,715 kWh of electricity per year. If you buy the average 340-watt solar panel, you’d need around 20-24 solar panels to generate enough energy to power your entire home. But as I wrote above, you have to consider many other factors.

Living in a 100% solar-powered house is possible with a solid initial investment and a proper setup. It will make your home more eco-friendly, and it will be good for the environment. Besides, this is a long-term investment and powering, heating, and cooling your home with solar energy will save you a lot of money in the future.

Source: https://home.howstuffworks.com/home-improvement/construction/green/run-house-on-solar-power.htm

"100% Solar-Powered House: a Realistic Goal or an Unattainable Dream"

How to Choose the Right Solar Inverter for Your Solar Power System (Part 1)

Photo by Alex Csiki from Pixabay

The solar inverter converts direct current (DC) electricity generated by your solar panels into usable alternating current (AC) electricity used by household appliances. If you have decided to go solar and install solar power system for your home, you have to do some research and have an initial knowledge about the solar inverter. 

The solar inverter consists of complex power electronics and software and it is crucial to the performance of your solar power system. When you choose your solar panels for your home it is important also to consider buying the right solar inverter for your solar power system. In this post, I’ll give you some basic information about solar inverters, their types, how they work, the best brands, and how to size an inverter to be right for your solar power system.

There are three groups of solar inverters: grid-tie, off-grid, and hybrid. There are three main types for grid-tied solar power systems: string inverter, microinverter, and string inverter + power optimizer. 

String inverters are central inverters and they are the most commonly used inverters for home solar power systems. When few solar panels of the same output voltage and power are wired together in series we have what is known as a "string”. All of the energy the panels produce is sent to a single inverter that is typically located on the side of your house, garage or utility room. String inverters are easy to install and maintain, and they also have the lowest price. 

This type of inverter is suitable when your panels are not facing multiple angles and have no shading issues. The disadvantage here is that if one panel is in shade and suffers reduced output, every panel in the string drops to that reduced output. 

Microinverters are small devices also known as module-level power electronics (MLPEs) that are attached directly to each solar panel, usually on the back. Thus they need to be designed to be resistant to humidity and heat. Microinverters convert DC power to AC right at the panel, providing a better performance of the solar array thus better performance of the whole solar power system. Just make sure the microinverter capacity matches that of the solar panel.

Microinverters allow you to monitor individual panel performance, giving you a more clear view of efficiency. Also, if something goes wrong with a particular solar panel, you can fix it easily. Because of all of this, and the need for multiple inverters, microinverters are the higher cost option. Besides that, another disadvantage is that they are located on the roof, so their maintenance is complicated. 

Power optimizers are small devices as well that is located on the roof alongside or integrated with each solar panel, allowing for more accurate performance monitoring. But unlike microinverters, they don’t convert power from DC to AC directly. Instead, they simply “optimize” the DC electricity before it is sent to a string inverter for conversion into AC. 

Power optimizers, similar to microinverters, make the solar energy system more efficient, but you can buy them at a more affordable price. And like microinverters, maintenance and repair cost power optimizers are high with power optimizers given their rooftop location. Microinverters and power optimizers typically come with a 20 to 25-year warranty while standard inverters typically have 12 to 15-year warranties.

Microinverters and power optimizers (together referred to as module-level power) are gaining popularity in residential solar markets. It’s always nice to have options, and string inverters and MLPEs each have pros and cons. 

The three best string solar inverters for 2020 are: Fronius (Primo and Galvo), SolarEdge (SE and HD wave), SMA (Sunny boy series). Enphase is a leading manufacturer of microinverters.

The inverter sizing refers to choosing the right size of solar inverter for your solar power system. As a general rule of thumb, you’ll need an inverter that matches the watts of your solar panel installation, For example, if you have a 3kW solar panel system, then you would install a 3kW inverter. In the case of microinverters, the size of the inverters should correspond to the energy output of each solar panel they’re connected to versus the entire system. 

If you plan to go off-grid, to choose the right inverter for your solar power system you must calculate the load your inverter can handle. You should know that inverters are rated in continuous/running watts and surge/peak watts. It’s important to consider both the continuous load and surge load when it comes to inverters (inverters have two capacity values printed on the manufacturer’s label: continuous watts and surge watts).

Surge watts are the amount of power the inverter can support for a very short time, usually no longer than a second when the appliance starts up. Appliances with motors require about 1.5 to 2 times the running wattage before the motor will start. Appliances and tools with induction motors such as refrigerators, freezers, air conditioners, microwave ovens, and pumps, need a much higher power level at startup. They may require a start up surge of 3 to 7 times the continuous rating.

Find out the appliance’s description and read the specific wattage requirements. If the wattage of the appliance is not listed on the specification, you may calculate the standard watts each of your appliances requires using the formula:

Amps x Volts = Required Watts

For example, if you have a microwave 7.5 amps x 120 (using a 120-volt ac) = 900 watts. It means that the inverter has to handle both the 900 running watts and the 2,700 watts surge requirements of your microwave. 

If the running wattage of your fridge is indicated as 600 watts, the surge wattage will be about 1,800 watts, but this surge is needed for only a fraction of a second. To run this refrigerator, you will need an inverter that can handle 600 running wattage and a surge of about 1,800 watts for a split second. At discount stores or home centers, you can find a typical inverter that provides 1,500 watts of continuous power and 3,000 watts of surge power. https://homeguides.sfgate.com/run-refrigerator-inverter-49672.html

For your inverter to be right for your system, its surge watts rating must be approximately equal to (or greater than) the potential surge watts of each appliance. You can find this out by looking at the label on the back of all of the appliances.

If you want to use multiple house appliances at the same time use the appliances running and surge wattage to determine which devices you can run simultaneously. Just add up all the continuous watt ratings of all the appliances that may be running simultaneously. The sum of continuous watts you get will determine if you're inverter can handle it. Always keep the running load under the maximum limit of your inverter.

With an inverter, with a continuous rating of approximately 1500 watts and with a surge rating of approximately 3000 watts, you can run a wide range of household appliances simultaneously by managing the running load. You can run LED lights, TV, stereo, laptop, fans, fridge, and a microwave (depending on the wattage) at the same time. Just put a current display meter to check the running load before you switch on a new appliance.

It is also recommended to provide a safety room of 10% - 20% watts (more than your largest load) when sizing up an inverter.

Remember: always seek professional help for the installation of your solar power system because of the specific power needs and circumstances of every home.

Next post: How to Choose the Right Solar Inverter for Your Solar Power System (Part 2)

Sources: unboundsolar.com, altenergy.org, homeguides.sfgate.com, batteryspace.com 

Hybrid Solar Power System - the Best of Grid-Tied and Off-Grid Systems

The hybrid solar power system is a combination of grid-tied and off-grid solar power systems. This system is described also as off-grid solar with utility backup power, or grid-tied solar with battery storage. The hybrid solar power system comes with a special hybrid inverter (sometimes referred to as a multi-mode inverter) that can transmit direct current (DC) power to and from your batteries and provides alternating current (AC) power between the grid and your home when necessary. The hybrid inverter can simultaneously manage inputs from both solar panels and battery storage, charging batteries with either solar electricity or electricity from the grid.

The hybrid inverter takes advantage of changes in the utility electricity rates throughout the day. You can temporarily store whatever excess electricity your solar panels produce in batteries, and put it on the utility grid when you are paid the most for every kWh. And you can rely upon your battery stored solar electricity while electricity is expensive and switch to the grid when it is cheap. 

The ability to store and use your solar energy when desired is known as self-use or self-consumption. 

In case you have already installed a grid-tied solar panel system you also have a traditional inverter (solar inverter) which converts DC into AC. If you would like to have a hybrid solar power system you should buy battery storage and a separate battery-specific inverter. 

An option is to buy a hybrid inverter for your grid-tied solar panel system if you are planning soon to add battery storage. Thus you won’t need to purchase a separate battery-based inverter. The hybrid inverter can function as both an inverter for electricity from your solar panels and a solar battery. It combines a solar inverter and battery-specific inverter, so it can charge and discharge battery storage. On the other hand, there are some modern energy storage systems, like the Tesla Powerwall 2, which comes with an inverter already built-in, eliminating the need for a hybrid inverter. 

The hybrid solar panel system is configured in such a way that your home uses solar power first, then stored power in the battery, and then grid power. With a solar hybrid system, you are less reliant on the grid and solar battery storage is used as a back up when solar power is not available. When the stored energy is depleted, the grid is there as a backup, allowing consumers to have the best of grid-tied and off-grid solar systems. And the battery storage is discharged less frequently, which extends its life. It needs to be replaced less often and saves you the cost of purchasing a backup generator. 

The hybrid solar power system is at least half the price of an off-grid system but they are more expensive than an on-grid system – typically double the price of the grid-connected solar power system. The hybrid solar power system is also more complicated for installation and takes more space. 

In summary, the hybrid solar power system has the following advantages: 

• gives you a continuous uninterrupted power supply 
• stores solar electricity or low-cost electricity 
• allows using solar power during the peak times of the electricity grid 
• solar power is available during a blackout or grid outage 
• reduces the power consumption from the grid 
• you are not dependent on the weather conditions 
• gives you more independence than on-grid solar power system

Off-Grid Residential Solar Power System

There are three main solar power systems - grid-tied (on-grid, grid-connected), off-grid (stand-alone power system (SAPS), and hybrid solar (battery storage with grid-connection). Since I’ve already written about grid-tied systems, in this post I’ll give some basic information about off-grid residential solar power systems.

An off-grid solar power system is a solar panel system not connected to the grid. This means that you are completely independent of the utility grid and your solar system produces clean electricity for all your energy needs. The system consists of solar panels, an off-grid inverter, charge controller and rechargeable battery storage. An off-grid backup generator is an optional component. 

Before buying and installing an off-grid power system you should know your daily power needs. This will help determine which size system is appropriate for you. You can check out this off-grid system calculator to determine the size of the system for your off-grid home. Your solar panel system can be mounted on the roof or on the ground. 

The off-grid solar power system just like the other solar power systems works by generating electricity from solar panels. That electricity is direct current (DC), so it is converted using an inverter to alternative current (AC) and then it powers your home electronic appliances. AC is the standard form of electricity for anything that “plugs in” to utility power and it is a necessary form for the household appliances to work. 

When solar panels generate excess electricity it charges a solar battery (DC) via a charge controller. The charge controller is an essential component because it regulates the voltage and current that solar battery storage receives, to prevent overcharging and damage. And by saving the solar power in battery storage, it is possible to run your home appliances with energy from the sun, even at night or on cloudy days when solar panels produce less electricity. 

The off-grid solar power systems are much more expensive then on-grind systems due to the high prices of the batteries. It is suitable for one family home if you would like to gain complete energy independence, holiday houses, and especially for houses and farms in remote areas far away from the electricity grid. But although the off-grid solar power system is expensive this is a long-term investment that will save you money and deliver green, reliable power for decades.

See also: Solar Power Calculating Tools Online

What is a Solar Panel Kit for Home?

Solar panel kit is pre-packed solar equipment that after installation can form an operating solar power system for your home. Almost all solar kits come with everything you need to have a working solar system (complete equipment). For some kits you may need to buy additional items, so you should be careful. 

Solar panel kits can vary in price depending on their build, power generation, size, and components. Therefore, they can cost from a few hundred up to thousands of dollars. Once you choose and buy a solar panel kit, it will be shipped to your home and all you have to do is install it yourself (DIY- do-it-yourself).

Before buying a solar panel kit, you should do some research and calculations regarding current energy consumption in your home, and how it will change in the future. Thus you will know how much solar power and how many panels you will need. You should also decide whether your solar power system will be grid-connected, off-grid or hybrid.

Here are the basic components that you can expect in most solar panel kits: solar panels, solar inverter, batteries (off-grid), charge controller (off-grid), mounting hardware, wiring and connectivity parts. You can choose between two types of solar panels: polycrystalline and monocrystalline. Monocrystalline panels are more expensive, more efficient, and more heat resistant.

Solar panel kits are suitable for small homes. There are solar panel kits for large homes but as you go up in size (1,000W and more), solar installations become more complicated. It doesn’t make sense to install a large solar panel system yourself. And If you are not sure about your knowledge it is recommended to seek professional help. Installing your solar panel kit may save you money but keep in mind that it can be time-consuming, challenging, and even risky in terms of safety and how to do it right. Also, if your solar panel kit is grid-tied you have to check whether your utility company allows self-installed solar systems to connect to the grid. 

If you are absolutely beginner to solar electricity it is a good idea to buy a solar starter kit. Starter solar panels kit won’t be able to fully power your home but it is just a few hundred dollars and includes the parts you need to start seeing if solar is right for you. It can power some of your electric appliances and it is usually grid-connected, which means that it will work with the existing grid. Typically solar starter panels ranging from 50W - 400W.

Solar panel kits are a good option for garages, farms, boats, caravans and off-grid cabins.

More detailed information you can find here:

https://www.letsgosolar.com/solar-panels/solar-panels-kits/

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GoGreenSolar.com - The #1 Online Destination For DYI Solar Kits - Shop Now

Basic Things to Consider Before Buying a Solar Electric System

Installing a solar power system requires very careful initial planning. First of all, you need to know exactly how much electricity your home uses each month. You may look up in your old electricity bills but also you should think about how your electricity needs will change over the next 10 years.

Solar photovoltaic panels can be installed on the roof, along a wall of the property or as standalone systems. If you are planning to install them on your roof, you need to make sure that the roof is strong enough to hold a solar panel because some of these panels can be quite heavy. A roof inspection (and any necessary repair) is recommended prior to a PV installation. Another thing you need to know is that the more sunlight modules collect, the more electricity they produce, thus the more energy your home will receive. Make sure that the roof (or wherever you intend to install your solar panels) is clear of any obstacles, such as trees or buildings, especially during peak production hours between 10am and 2pm.

Ideally, a solar system will go on a south/southwest-facing roof, although east and west facing roofs are good candidates, as well.

You should decide whether your system will be grid-connected, off-grid or hybrid. With a solar PV system connected to an electric distribution system (grid-connected) you can receive back-up power from it when your system doesn’t produce enough energy for your needs. When your solar PV system produces excess power, that electricity can be send back into the grid, and your local utility is required to buy it from you.

Picture: apps1.eere.energy.gov

A grid-connected solar power system is easily integrated into the existing electrical infrastructure of a house and the system can provide decades of reliable and environmental friendly electricity production.

A stand-alone (off-grid) solar PV system is independent of an electricity distribution grid operated by a utility. The electricity is provided by solar power alone and stored in a battery for later use. Such systems typically make sense in remote locations.

The average solar PV panel last approximately 30 years and many manufacturer warranties last for up to 20-25 years. Solar PV panels are designed and installed to be low-maintenance. However, it is very important to have your solar panels cleaned regularly because they benefit from being hosed off with water twice a year, especially after long periods without rain. Dust or dirt may cause a 10-15% reduction in their efficiency.

Before buying and installing the panels it is also essential to make sure that you understand the installation regulations in your local area. In most cases it is wise to check with the local authority before installing your solar electric system.