Wednesday, July 17, 2024

How Does Solar Feed Back Into The Grid

What Happens To Excess Solar Power Production

Solar Residential Part 3- Inverter and Power Grid Connection

In most households, energy usage during the day is relatively low as members tend to be out of the house. This is also when solar panel production is at its peak, so power generation far exceeds energy use.

With grid-tied systems, this excess power is exported to the utility, which earns electric bill credits for the homeowner.

How Much Do Solar Panels Cost What Is The Payback Period

The cost of a solar power system varies depending on the size of installation, your architecture, and your location. A typical Edmonton, Saskatoon or urban net-zero home solar panel installation will range from $10,000-$20,000 depending on your energy needs. There are many factors to consider when assessing the cost of solar panels in Alberta such as the size of the array, the available roof space, your location within Canada, and the ease of installation. Read more detail on the cost of solar panels in Alberta, Saskatchewan and BC.The best way to find out how much home solar panels cost is to contact us for a FREE appraisal!The payback period of solar power systems will also vary depending on the size of installation, how ideal the location is, and your personal energy consumption. Systems will generally pay themselves off in 10-15 years but that is a misleading number. What’s important is the long-term economics of solar panels. The true payback of solar panels is best assessed by comparing the levelized cost of electricity of solar vs the levelized cost of standard energy . The levelized cost simply means the total money spent on fuel over 30 years divided by the total amount of energy generated by the fuel. Solar energy has a lower LCOE than standard energy so you save money over a long period.

The Different Forms Of Inverters

In off-grid applications, DC electricity is saved in batteries.

An inverter changes the voltage from the batteries into usable AC power.

The inverter must be large enough to power all the appliances and accessories that will be running at the same time and must be able to control surges of power from clothes and dishwashers, dryers, etc.

Grid-tied inverters supply power to the home when required, supporting any excess energy into the grid.

They include advanced detection devices which ensure they shut down when a grid outage is detected or when business workers require to work on the grid.

As you can see, an inverter is necessary if any or all your power comes from solar panels.

Advances in inverter technology are being made all the time, with the main disadvantage being the lack of efficiency, since most inverters work at only 90 to 95% power.

Acknowledging the inner workings of an inverter is not essential, but selecting the right inverter for a particular application is, so consulting a solar professional or company on the right inverter to buy is very desirable.

You can buy the best things online.

For buying online, you can visit .

What Are Grid-Tied Inverters?

Grid-tied inverters are the critical element in a grid-tied renewable power system. Theyre most widely used in Photovoltaic systems.

The term grid-tied means that the house is still attached to the local utility energy grid.

Options For Using Grid-Tied Inverters

How Do Grid-Tie Inverters Work?

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What Are Solar Thermal Technologies

There are two types of solar thermal systems: Passive and active.

Passive solar technologies are the oldest ones still in use. Typically, a passive solar system involves the strategic location of buildings and elements such as windows, overhangs, and thermal masses. Such practices take advantage of the sun for lighting and space heating to significantly reduce the use of electrical or mechanical equipment. These techniques make for more energy efficient buildings. Another example is a solar cooker or oven, which can easily bake cookies or your meal on a hot day.

Active solar thermal systems use sunlight to heat domestic water, or for space heating, pool heating or other heating applications. Solar heated water is stored in a hot water tank so it can be used at night or the next morning. In some space heating applications, a solar heated fluid is run through pipes within the home to provide radiant heating, typically used in floors and walls. There is no grid for residential heating so the thermal energy must be stored on site or dissipated. Geothermal heat exchange systems can also be used to cool homes in the summer and heat them in the winter. Systems can range from 200% 500% efficient.

Equipment required for an active solar thermal system

The major components of solar thermal systems are:

Do Solar Panels Work On Flat Roofs

Infographic on How Does Solar Power Feed Back Into The Grid?

While most solar panels are tilted, solar panels can work just as well on flat roofs, as they use special mounting frames that allow them to be tilted at the best possible angle. There are added benefits, in that flat roofs:

  • are easier to access, making installing and maintaining panels much easier
  • do not need tiles taken up
  • make the panels less visible from the street

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How Does The Grid Work

The grid is how we get our power. Its also how electricity is transmitted and distributed to your home or business.

The electricity generated by a utility company is distributed through transmission lines which run on high voltage, up to about 230 kilovolts .

This makes the lines very efficient, but also dangerous.

Power transformers then change the voltage to a safer level for use in homes and businesses, usually somewhere between 100-240 volts AC .

This is how power reaches your outlets!

The grid itself acts as a kind of an electrical circuit it allows electricity to run through these high voltage wires to your homes, but if there is a disruption in the grid then it stops that flow of electricity.

What Happens If It Snows Or Hails

How do solar panels fare against snow or hail? Naturally, snow and hail are two of the main concerns for residents throughout Alberta, Saskatchewan, BC and Northern Canada. Rest assured, snow does not have as great of an impact as you might think. The slope of the panels, as well as the current running through the solar panels, will prevent much of the snow from settling. Additionally, the energy generation and payback period are calculated based on annual production values, the majority of which comes during the spring/summer/fall months. If some snow does settle, the added energy generation plays a minor role in the systems overall life since solar radiance is significantly diminished in the winter. It is not worth the risk/hassle of climbing onto your sloped roof to clear snow. These results are documented in a study conducted by NAIT for Edmonton’s conditions.Read the study conducted by NAIT on the effects of snow coverage and tilt of solar panels.Hail! Dont worry, your solar power system is built to withstand severe Canadian hailstorms! Solar arrays have been tested with golf ball sized hail at 100kph and the results show hail does little to impact PV modules. Kuby Energy is yet to see a single case of hail damage against solar panels installed in Saskatchewan, Alberta or BC.

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Home Solar Panels And The Grid

When a homeowner decides to add solar panels to their home, in most cases they will choose to be grid connected. This means that the home can get electricity both from its solar panels and the electric grid.

This is important because solar energy is intermittent: it stops working when the sun sets. When this happens, a grid-connected solar home will use electricity from the grid to meet its needs. This process happens automatically and is seamless to the homeowner.

In the other case, when solar panels generate more electricity than a grid-connected home needs, it will send its extra electricity into the grid. That solar electricity will then get used by the neighborhood. No electricity gets wasted.

Net Metering And Grid


On a sunny day, itâs common for solar homes to send excess electricity into the grid in the middle of the day when power generation is at its peak. How you receive credit from your utility company is dependent on a policy called net metering.

Adequately describing net metering requires an article by itself – which you can read here – but the graphs below give you a quick idea of what it looks like over the course of a day.

In the first graph, you can see that when the sun isnât shining, a solar home will pull power from the grid, and tend to generate excess electricity in the middle of the day.

With net metering, you get full credit for the extra electricity sent into the grid, which is used to offset any power that you need to draw from the grid at night or when solar power generation is low.

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The Five Key Components Of A Solar Panel System

What are the components of a solar panel system?

Have you ever wanted to hear a breakdown of all the components that make up solar panels? Even though it may seem like magic, its actually science and engineering. There are 5 key components in a home solar panel system: solar panels, an inverter, an electrical panel, the power grid, and the sun. In this blog, SOLARPARTS will walk you through how each component works together to create a complete solar panel system.

  • Solar Energy is harnessed from the sun
  • Every solar system collects energy from the sun. A solar system does not create the energy, but instead converts energy from the sun into electricity your home can use. A standard solar panel consists of a layer of silicon cells, a metal frame, a glass casing, and various wiring to allow current to flow from the silicon cells. Silicon is a nonmetal with conductive properties that allow it to absorb and convert sunlight into electricity. When light interacts with a silicon cell, it causes electrons to be set into motion, which initiates a flow of electric current. This is known as the photovoltaic effect, and it describes the general functionality of solar panel technology. That means as long as the sun is shining, your panels can generate energy. Even on cloudy days, your panels can still generate electricity thanks to the sun’s rays breaking through the clouds.

  • Solar Panels absorb sunlight
  • The Inverter converts the energy
  • Your home is powered by solar
  • What Is A Grid Tie Solar System

    A grid-tie solar system is a way of using renewable energy in your home or business.

    The idea behind it is that if the sun is shining then you will not be consuming power from the utility company, so you will just use the electricity your solar system is generating.

    However, at night or when there are clouds in the sky your solar system wont be able to generate enough energy to fully power your home.

    And here comes the benefit of a grid tie solar system.

    Because your system is still connected to the grid , you will still be able to drain electricity from your utility company if your solar system isnt generating enough energy for your usage.

    Not only that, in case your system is generating more electricity than you actually use, you will be able to sell this energy back to your utility at a premium price via net metering.

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    The Partial Array Challenge

    There are instances when plant owners approach us here at Alencon about installing SPOTs on only part of an array in order isolate a particularly underperforming part of the plant and save money by only having to do a partial retrofit. This can occur in situations where part of the array is experiencing abnormal shading or has perhaps suffered from significant module damage or failure. The SPOTs can improve performance in mismatch conditions by isolating underperforming strings and performing string level maximum power point tracking on them to assure they perform to the best of their ability.

    However, when doing such partial retrofits, the possibility of back feed under certain circumstances is being introduced. For example, if the same combiner box which SPOTs and other non-SPOT connected strings is manually opened during operation, the SPOTs will continue to load the strings to which they are attached and may then potentially push power into the strings to which they are not attached since those panels are no longer connected to the DC bus. An easy solution in this case is just to install appropriately rated DC isolators between the SPOTs and the PV strings and make sure to open the isolators before opening the combiner.

    Figure 2: Shows what back feed can look like when a combiner is opened with SPOTs on a partial array with no other protection.

    What Happens With Grid Connect Systems During A Blackout

    How Does Solar Power Feed Back Into The Grid?

    The grid connect inverter will automatically shut itself off within a few milliseconds of a blackout. This avoids the potential of a dangerous brown-out in your home and to prevent back feeding into the grid. Therefore even though you have a solar system during a blackout you will not have power available. If you want to keep on having electricity available during a blackout then you would need back up batteries. This will add to the cost of the system.

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    What Is Solar Energy

    Solar energy is energy from the sun in the form of radiated light and heat. The suns radiant energy can be used to provide lighting and heat for buildings and to produce electricity. It is a renewable resource and unique for its ability to generate energy in a quiet, clean, and consistent manner over long periods of time.

    Solar energy can be harnessed only during the day and only if the sunlight is not blocked by clouds, buildings or other obstacles.

    Solar thermal and solar PV are the main techniques and technologies used today for producing/generating solar energy. Other types of solar energy systems include solar air heating, which is usually applied on commercial and industrial buildings, and concentrated solar power systems, which were more common in the past, and at a utility scale.

    Given Albertas cold climate and relatively large heating demands, homes with solar heating systems also typically have other methods of heating, especially during short winter days.

    Terminology and how energy is measured for solar systems.

    If you encounter a term that you are unfamiliar with please refer to our Glossary.

    Electricity is measured in kilowatts . Electrical energy is the amount of electricity used in an hour and is measured in kilowatt-hours . The average Alberta home uses 600 to 800 kWh per month as is shown on the monthly electric utility bill.

    Is My Building Suitable For A Solar Power System

    Several aspects will need to be evaluated to determine if your home is a good solar site, such as orientation, space available, shadows on the space available and your current electricity usage. The best site will be one with adequate north-facing roofs that have no shade. Variations on that will cut into the productivity of the system.

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    Should I Change The Angle Of My Array Manually Throughout The Year

    Most on-grid system owners do not change the angle of their array ever. On-grid system arrays are typically bolted into a set position.

    Off-grid system owners have greater needs during the winter months. Therefore, it often makes sense for them to change the tilt twice a year, at the spring and autumn equinoxes. Changing the tilt angle twice a year will typically increase annual production by 4-5%. Ground mount arrays are usually easier to access than roof mounts.

    If you have an off-grid system that you plan to change the tilt of, we recommend that you ensure your solar array has been designed to allow for you to manually adjust the angle of the solar modules in a safe way. All other adjustments should be made by an electrical professional.

    What Are Ideal Conditions For Solar Panels

    Solar Electricity: Connecting inverter to grid

    An ideal roof for solar panels will be facing due south with a slope close to the latitude of the region. For Edmonton, Alberta, solar panels mounted at 45 degrees to 53 degrees are ideal, however slopes from 18-60 degrees still operate at a very high efficiency. If the slope of the roof is fairly shallow, it is not as inefficient as you might think. The study cited above by NAIT showed that a systems efficiency will only drop by less than 10% annually. East/West faces are effective for commercial or home solar panel installations but will experience a minor reduction in efficiency. In select cases, facing east and west may actually be an advantage if the property requires the maximum amount of energy from a given building footprint such as with barns or mechanical shops.Most homes are suitable for solar energy and we will always be sure to let you know if it is an investment worth making. We don’t simply sell solar panels, we work with homeowners to assess viable investments in renewable energy.

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    What Equipment Do You Need For A Grid

    Grid-tied systems are the easiest solar systems to install. They require the least amount of equipment, as there is no onsite storage equipment or wiring to deal with.

    Here are all the components you need for a grid-tied solar system installation:

    • Solar panels: These will generate DC electricity. A typical 6 kilowatt solar power system would require roughly 20 individual panels.
    • Racking and mounting: These serve to hold the solar panels in place, as well as allow for ventilation to cool the panels.
    • Wiring: This conducts the power from the solar panels to the inverter, and then onwards to the home or net meter.
    • Solar grid-tie inverter: The grid-tie inverter converts DC electricity from the panels into alternating current electricity usable by both the house and grid. It also assesses energy flows in real time to determine if solar output should be used in the home or exported. There are three types of solar inverter: string inverters, string inverters paired with power optimizers, and microinverters.
    • Net meter: This is a meter that allows and monitors the two-way exchange of power between the home and utility company. If not already installed in your home, the net meter will be provided by the utility once the grid-tied solar system is ready to be connected to the grid.

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