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Solar (PV) panels generate electricity by capturing photons from sunlight. They can’t do that at night. But just because solar panels can’t produce electricity at night, the right solar power system can keep your home running and save money even when the sun doesn’t shine.
A solar battery allows you to store the electricity your solar array collects during the day for use at night or when cloudy weather reduces energy generation.
For on-grid solar systems, you can use solar batteries and programs like net metering to maximize your savings on utility bills by using stored electricity during on-peak billing hours and selling excess electricity back to the utility company.
Learn more about each approach below.
What are Solar Panels?
Solar panels are multiple photovoltaic (PV) cells that capture the photons from sunlight and convert it into direct current (DC) electricity.
A portable power station or other balance of system then converts DC into AC (household) electricity for use with your personal devices and home appliances.
There are three main types of solar cells used in residential solar arrays.
- Monocrystalline silicon (Most efficient, typically more expensive)
- Polycrystalline silicon (Less efficient, more eco-friendly, cheaper)
- Thin-film (Cheapest and least efficient, but suitable for some applications)
When selecting solar panels for your home, the most crucial specification to consider is efficiency. With PV panels, efficiency measures how much available sunlight the solar panel will convert into electricity per square meter (M2) of surface area.
Monocrystalline solar panels have the highest efficiency — up to 23%. Poly panels average around 15%. Thin-film panels often have an efficiency rating in the single digits.
In practical terms, the more efficient the PV panel, the more electricity you will generate during peak sun hours using less space (and potentially fewer panels).
Over the long term, efficiency can be a significantly more important consideration than price. The more electricity your solar panels produce, the more you save on utility bills, the bigger your return on investment, and the faster you achieve solar payback.
(Source: Energy Education)
Can Solar Panels Produce Energy at Night?
Solar panels require sunlight to generate energy using the photovoltaic effect. The sun’s light travels to the panels as photons. When a photon hits the solar cell, it dislodges an electron from the cell, which creates an electron space. There are two wafers within each cell, one with added phosphorus to create free electrons and a negative-charged environment, and one with added boron to create receptor holes for electrons and a positive-charged environment.
As the electron space is made, the electric field within the cell shifts the space to the positive environment and the electron to the negative. As the electron travels the long distance back to its original spot, it creates the current of your PV system, which flows out of the panels, through inverters, and inside your home to be used.
Without the sunlight providing photons for the solar cells in your PV panels, there’s no energy to capture.
Solar panels do not work at night.
But that doesn’t mean your solar power system won’t work for you around the clock.
It can keep your whole home running and save you money on your utility bills — even with a grid-tied system.
Battery Storage
A portable power station or solar battery is essential for off-grid solar power systems.
Like other forms of clean, renewable energy — such as wind — solar power is intermittent. Solar panels or other photovoltaic modules can’t capture energy at night.
Even on sunny days, solar panels rarely capture their full rated power. Electricity production will be reduced on overcast days with little or no peak sunlight.
Without a solar battery to store electricity generated during the day, an off-grid solar system would have no way of powering your home (or anything else) at night.
Solar batteries aren’t required with grid-tied systems, but they offer many benefits.
As long as the grid is operational, the intermittency of solar isn’t an issue. Your balance of system will automatically switch to on-grid electricity if you’re consuming more power than your solar panel array generates.
But next time there’s a power outage, you’ll end up in the dark like everyone else.
Blackouts are becoming more frequent due to extreme weather, aging infrastructure, and demand often exceeding supply. Utilizing a solar battery with adequate storage capacity as a home backup provides energy security even when the grid goes down.
But the benefits of solar batteries don’t stop there.
Most utilities charge for electricity at on-peak and off-peak rates. If your off-grid solar power system’s primary function is to back up essential appliances during a blackout, consider putting it to work during peak billing hours.
If you power your home for 4-5 hours a day during on-peak hours using solar and primarily use grid electricity off-peak, you can save a substantial amount of money every month.
The same principle applies if you only use solar to generate electricity for part of your home. For on-grid solar systems, adding a solar battery allows you to follow the same strategy and only use electricity that you pay for off-peak.
(Photo: deepblue4you)
On-Grid Solar and Net Metering
Grid-tied solar power systems work together with existing utility infrastructure to help ensure you always have uninterrupted access to electricity. During times — like at night — when your solar array isn’t producing electricity, your system automatically switches over to on-grid power.
But that doesn’t have to mean you have to PAY for the electricity you can consume.
When your solar panel array isn’t generating electricity, one option is to use battery storage, as covered above. The other option to offset (or eliminate) your utility bills with a grid-tied system is to take advantage of net metering.
Net metering is a program offered by most states and utility companies. Any electricity your grid-tied solar power system generates in excess of your consumption is sent back to the grid.
For your on-grid solar power system to be eligible (and functional) for net metering, it must include these components (in addition to solar panels):
- Grid-Tie Inverters
- PV-Ready Distribution Board
- Smart Power Meter
Because you’re feeding power back to the grid, it must be conditioned to be identical to the electricity the utility produces. To be net metering eligible, your solar power system has to meet numerous standards and requires professional installation.
If your solar panel array generates enough electricity to meet (or exceed) your household consumption, you will be credited for the on-grid power you use at night.
In some cases, you may actually MAKE money from your utility provider!
Do Solar Panels Work in Cloudy Weather?
Solar panels still capture energy in cloudy or overcast weather, though they won’t be as productive as on sunny days. Most panels generate around 10-25% of their rated power on an overcast day.
With EcoFlow off-grid solar systems — like the whole home generator — you can always check the smartphone app to monitor consumption and production.
Frequently Asked Questions
No. Solar panels produce electricity using the photovoltaic effect. Without the photons captured from sunlight, solar panels can’t generate electricity. Because solar power is intermittent, you will require a solar battery or grid-tied system to provide electricity at night.
Solar panels don’t produce electricity at night. You need a portable power station or solar battery to store power for use during hours without sunlight. The other option is to invest in a grid-tied solar power system. With on-grid solar, you draw electricity from your local utility when required. You may be eligible for net metering, enabling you to sell excess power you generate but don’t consume back to the grid.
Solar panels still generate electricity when the sun isn’t out, though they won’t be as productive. On-grid or off-grid solar power systems generate a smaller percentage of their rated power on cloudy days. White fluffy clouds affect electricity output less than thick, dark clouds.
Yes, solar panels can charge a portable power station or solar battery on cloudy days. However, their power output will be lower than on days with peak sunlight. The higher your solar panels’ efficiency rating, the more power they will produce on both cloudy and sunny days.
Final Thoughts
Solar panels require sunlight to produce electricity.
Portable power stations and solar batteries make off-grid solar a reality by storing electricity for consumption when the sun isn’t out.
If you opt for a grid-tied system, you can draw power from your local utility to make up for any shortfall in electricity production. You may be eligible for net metering programs to offset or eliminate your electricity bills.
When shopping for PV panels, remember that the higher the efficiency rating, the more electricity the panel will generate on cloudy or sunny days.
EcoFlow’s Solar Panels utilize monocrystalline silicon to offer industry-leading +/- 23% efficiency.
Whether you opt for on-grid or off-grid solar, maximize your available surface area with high-efficiency rigid, portable, or flexible solar panels.
