Solar Panels and EV Charging
The ability to charge an EV using Solar Power is one of the main benefits of having rooftop solar. The expense of an electric vehicle's "fuel" can effectively be eliminated by charging with electricity produced by your own solar panel system. But in reality, it's not always as simple as it seems. Various home Solar EV chargers are covered in this article along with an analysis of solar charging choices, a time estimate for charging EV with Solar Panels, and a few drawbacks of charging EV Solar Panels.
How to use Solar EV at home
The size of solar system, the time of day, and the weather are the three most obvious variables that affect how easily you can charge an EV With Solar Panels. If you want to swiftly charge an EV using solar power alone, you will need a large enough solar array and assistance from a smart charger, which we will go into more detail about later.
Depending on the following elements, solar charging for EVs might be either difficult or simple:
1. Depending on the charger type, speeds can range from 2 kW to 22 kW.
2. Size of your solar system Solar power installations on rooftops typically range from 5kW to 15kW.
3. How much more battery power do you need to add to the car?
4. How frequently do you drive, and how far?
If you don't drive much, using a straightforward portable plug-in (level 1) charger and a very small 5kW solar system can make charging an EV at home with solar power simple. Even with a much larger solar array, it can be challenging to charge an EV using a stronger level 2 charger, as will be discussed later. The issue arises when, in cloudy or inclement weather, the solar system frequently cannot produce enough electricity to fully cover a level 2 charger. Fortunately, smart EV chargers and a number of alternative solar charging methods described above can aid in this situation.
EV battery capacity - Kilowatt-hours (KWh).
Understanding EV battery capacity and range is essential before going into too much depth about the various charger types and charge rates. Electric vehicles are available with a wide variety of different battery sizes, ranging from 24kWh up to 100kWh or more. Battery capacity is measured in kilowatt-hours (kWh). The majority of ordinary EVs have batteries with a capacity of approximately 65 kWh, which, depending on the environment and how effectively you drive, typically offers a driving range of about 350 km.
The driving range per kWh of battery capacity ranges from 5 to 8 kilometres. In the real world, lighter, more effective EVs can consume as little as 12kWh per 100km (1kWh = 8.2km), but larger, high-performance EVs can require 20kWh or more.
Due to increased aerodynamic drag, driving at greater speeds reduces driving range. Regenerative braking, which recovers much of the energy generally lost during braking to slow the car, is another feature found on the majority of EVs. In city start-stop driving, where it increases efficiency and lowers brake dust and air pollution, regenerative braking is very helpful.
Domestic EV Charging Options
After acquiring an EV, folks who have solar installed immediately consider what charging alternatives are available and whether they are compatible with a rooftop solar system. Before we go any further, it's important to note that the majority of level 2 chargers, also known as wallbox chargers, are comparatively easy to install on any home or business, rooftop solar or not. Your utility grid connection's ability to sustain a level 2 charger, which typically needs a 32A supply, is the main challenge.
Only the first two of an EV charger's three levels, which are technically available, can be utilised at home. Simple portable chargers known as Level 1 are included with the majority of EVs and may be plugged into any conventional 10A power outlet. Compact wall-mounted chargers from Level 2 are placed permanently in residences and commercial buildings. Large, strong, fast chargers known as Level 3 are typically found at designated roadside EV charging stations.
Types Of EV Chargers for Domestic Use
1. Portable plug-in socket chargers - (Level 1) 1.4kW to 3.6kW.
2. Single-phase home EV chargers - (Level 2) 3.3kW to 7.4kW.
3. Three-phase home EV chargers -(Level 2) 7.0kW to 22.0kW.
4. Combined solar inverter and EV charger - (Level 2) 5.0kW to 7.4kW.
How long does it take for a EV to charge through Solar Power?
Given that it depends on the size of the solar system and the capacity of the EV battery, this is an open-ended question. A typical 6.5kW rooftop solar system will typically require a long bright day to charge an average EV from 20 to 80%. When it comes to charging EVs at home, obviously, the more solar power the better, especially in places that are colder and less sunny. If you are at home during the day and don't drive more than 80 km per day, using a standard rooftop solar system for EV charging will be rather simple.
The actual charge time can vary greatly depending on the EV charger type, the weather, and how low the EV battery is. On a sunny day, a bigger 10kW rooftop solar array with a more potent 7kW Type 2 charger could charge an EV up to 80% in 6 to 8 hours, while a bigger 15kW solar array and more potent 3-phase charger could do so in as little as 5. Many of these charging periods presuming low household load and largely sunny weather, but in reality, things aren't always perfect. If you want to charge your EV at home without paying for grid power, here is where a smart EV charger can be useful.
Efficient Charging of EVs
The charge rate, ambient temperature, battery temperature, charging cable length, and the effectiveness of the vehicle's power conversion system are just a few of the variables that affect how efficiently an average EV charges using a household EV charger. For a variety of reasons, temperature can significantly affect the effectiveness of charging. High ambient temperatures may necessitate running the battery cooling system while the battery is charging, whereas extremely low temperatures necessitate running the battery heating system while the battery is charging. Additionally, due to increased electrical resistance in extremely high temperatures, any charger will function less effectively.
As an electrical current passes through a cable, resistance and the resulting voltage drop cause cable losses. Three key factors—the charging current, the cable length, and the cable size—determine the degree of voltage drop; longer cables and higher currents lead to more losses. Higher temperatures also cause the cable resistance to increase, which lowers power and causes a voltage drop. Longer cords, particularly extension leads used with portable chargers, cause more losses, as the test results above show. High temperatures can also cause the losses to increase, especially if the charging wire and extension leads are left out in the sun.
Low charge rates equate to less efficiency
Electric vehicles (EVs) are no different from other power conversion equipment in that they run more effectively when operating close to their rated power output. In order to charge the battery system in an electric car, the built-in charger must change AC electricity from the grid into high-voltage DC power. Power conversion (using transistors) and powering auxiliary controls, such as battery cell balancing and temperature regulation, are required for this operation. The losses will be bigger if the charger is rated at 7kW but the charge rate is only set at 2kW. The efficiency of charging can be increased by charging at a rate of at least 50% of the charge rating.
EV Smart Chargers
To optimise when and how your EV is charged, smart EV chargers offer a variety of smart charging modes. There are several charging choices, including boost charging, solar-only charging, scheduled charging to charge automatically during off-peak hours or when electricity prices are low. If you have rooftop solar installed, you may maximise your own solar use by using a smart EV charger. Instead of exporting extra solar to the power grid, these intelligent app-controlled chargers can keep track of your solar generation and direct it to your EV charger. This prevents you from having to use the grid to power your EV during bad or sporadic weather.
How smart EV chargers work
Depending on the charger type and settings, a typical home EV charger will consume a fixed amount of power, often between 3.5kW and 7.4kW. The energy produced, especially in cloudy or bad weather, may be much less when charging from rooftop solar, though. This issue is solved by smart EV chargers, which monitor energy flow to and from the grid using a CT clamp, an energy metering device installed close to the main electrical supply connection. When it notices that your solar system is producing more energy than is needed, it will start charging the EV at that exact rate. Smart EV chargers automatically modify charge rate to match excess solar generation because this can constantly change as a result of variations in power usage and solar generation.
V2G and V2H bidirectional chargers
Vehicle-to-grid, or V2G, is a new technology that will gain popularity in the future. It uses a bidirectional charger. Although it may seem complicated, this merely permits energy to move to and from your electric vehicle. Bidirectional EV chargers can pull power from your vehicle to power your home or help balance the electricity grid during periods of heavy demand, in contrast to conventional EV chargers that only transmit energy in one direction during charging.
Vehicle-to-home, or V2H, technology is another new development. Similar to the V2G, but with the energy being utilised locally to power a home, this enables the EV to operate much like a sizable household storage battery to aid in increasing self-sufficiency with solar.
There are just a few EVs on the market that are V2G compatible, including the most recent Nissan Leaf, and they must be able to accept two-way charging for V2G to function. This innovation will soon change the game and can provide a variety of services, such as powering your home and storing extra solar energy.
Vehicle-to-Load - V2L
EVs that use vehicle-to-load, or V2L, technology are significantly easier to operate and don't need a bidirectional charger. Electric appliances can be directly plugged into the vehicle's built-in standard (10A) AC outlets thanks to V2L. In the case of a blackout or other emergency, EVs equipped with V2L technology can supply AC power and be used as a backup power source. Given that the majority of EVs have batteries of 60 kWh or more, a completely charged EV could theoretically supply a typical household for several days without interruption. Another helpful aspect of V2L is that it may be used to recharge other electric vehicles if their batteries run out, leaving them stranded.
EV charging using a battery
It can be difficult to use rooftop solar to charge an EV if you are gone for the majority of the day. But this is where battery storage comes in handy. Most typical residential battery systems have a 10kWh capacity, which, if used for charging, can deliver up to 80km of driving range. As a result of home consumption constraints, only half of the battery may really be usable, resulting in a driving range of only 30 to 40 kilometres. But given that most people only travel small distances by car on average, this would be appropriate. Longer distance drivers will need a bigger battery or off-peak charging to power their car.
Single-Phase vs. 3-Phase Grid supply
Homes can connect to the grid via either a single-phase or three-phase hookup. A 3-phase home connection can provide up to 45kW, but single-phase connections are typically limited to 20kW or 80A. (3 x 63A).
In Australia, the majority of homes have a single-phase, 220 to 240V power. Typically, the maximum amount of energy that may be delivered by the electrical grid is between 12kW and 20kW. However, you can't utilise the entire grid's capacity to charge an EV because then you won't be able to use any other appliances simultaneously. If you did, the grid supply switch would shut off as a result of overload each time you used a toaster or microwave. Because of this, the majority of single-phase EV chargers have a 32A or around 7kW limit. Unless you truly need to fast-charge at home, this is not a bad thing. However, utilising an EV charger with load-balancing capability, which tracks household use and modifies the charging rate as necessary, higher charging rates can be enabled.
According to the electrical connection capacity of the building, it is possible to install one or more 22kW high-power EV chargers because the majority of commercial firms have a 3-phase supply. Smart load-balancing EV chargers are also advised because using several level-2 EV chargers could overload a business grid supply. Contact iGreen Energy to know more about EV Charging through Solar Panels. Our experts can help you with all queries about Solar EV and give you the best option for charging EV With Solar Panels.