Using a solar panel without a big battery bank and an expensive inverter is a common question when discussing solar power. The simple answer is yes, although there are certain conditions.
Here are some of the applications for straight DC solar power;
- Kitchen Appliances
- Home Electronics
- HVAC
Power drawn directly from a solar panel can do many things. Nearly every electric device using DC Current can run directly from a solar panel.
Of course, there are some limitations to straight solar. Let’s look at what can and can’t be done.
Straight Solar – Without Inverter or Battery
What a panel provides
A solar panel produces Direct Current (DC). Panels are generally rated as 12 volt or 24-volt panels. The maximum voltage produced by panels is often 30% higher than the nominal voltage.
This must be considered when setting using power straight from a panel. A voltage regulator or charge controller can be used to solve this issue.
See also: What Is A Solar Inverter? (Explained With Examples)
What a panel requires
The main shortcoming of a solar panel is that it requires unobstructed sunlight to provide power. Sun angle, cloud cover, and even a large bird passing over will reduce the effectiveness of a panel.
While these may be temporary conditions, they must be considered when planning a system.
What a Straight DC Solar Array can do
A sufficiently powered solar array can run nearly any appliance or electronic device. While most Solar-Ready devices are designed to use 12 or 24-volt DC power, the current required varies by device size.
A moderate-sized 12-volt panel can run a Television. It would take several large 12 or 24-volt panels to run an Air Conditioner.
STRAIGHT SOLAR CAN:
- Provide DC power during daylight hours.
- Run nearly any DC appliance.
- Charge personal devices.
STRAIGHT SOLAR CAN NOT:
- Provide power at night.
- Provide power in cloudy weather.
- Run AC-powered devices or appliances.
Products for DC Applications: Straight Solar
A Google search or trip to your local RV Supply store will reveal a wide array of DC-powered products. 12 Volt is not just for light bulbs anymore.
Most home electronic devices run on DC power. When we plug them into our 120 Volt AC grid power, a transformer inside the device converts it to an appropriate DC voltage.
Even those little chargers used to charge our cell phones are transformers converting 120 Volt AC to 2 or 3 Volt DC to charge the phone.
A wide variety of home entertainment devices are available. Most solar entertainment devices run on 12 Volt DC.
Kitchen Appliances
Just about any modern kitchen appliance is available in a DC version. Microwave ovens are the exception. There has not been a successful DC Microwave on the market yet.
In all cases, DC kitchen appliances tend to be smaller and operate more slowly than their AC counterparts.
Cooking
Creating heat requires a lot of power. Small toaster ovens and slow cookers are standard 12-volt cooking devices.
They are generally designed for truck drivers and campers. While small and slow, they provide a way to prepare meals using a straight solar power source.
Pros
- Straight from solar cooking.
- Inexpensive.
- Does not require gas.
Cons
- Small.
- Slow.
- Require substantial power.
Refrigeration
The Off-Grid movement has helped increase Straight Solar product availability. 12/24 DC Voltage refrigerators have been a beneficiary of the movement.
Chest Freezers, Fridge Only, and Freezer/Refrigerator units up to about 14 cu/ft are available. While such units could run straight from an array, batteries may be a good idea to make it through the night.
Pros
- 12 or 24 Volt Straight DC power.
- Do not require a lot of power.
- AC adapter is available.
- Variety of styles and sizes.
Cons
- Slow to cool.
- Small.
- Pricey.
- Won’t run at night without batteries.
Television
The advent of LED screens has made the 12 Volt DC television as common as regular 120 Volt sets. Straight DC units up to about 40” are available.
Some units have built-in DVD players, rechargeable batteries, and a wide assortment of input options (RCA, USB, HDMI, etc.). Most units also include a 120 Volt AC adapter.
Pros
- High-Quality Picture.
- Variety of sizes.
- Variety of features.
- Input Options.
- Reasonable 12-volt power requirement.
Cons
- Poor Sound Quality (Like most flat TVs).
- Narrow view angle.
Other Entertainment Devices
Any home entertainment device can run on 12 Volt DC Power. Stereo Speakers, CD Players, DVD Players, TV Sound Bars are all available.
A quick Google or Amazon search for “12 Volt…” will reveal a wide variety of toys operating on straight solar power.
Computers and Smart Phones
Ironically, computers and phones which run on batteries can be a little tricky to charge on straight DC power. A desktop computer has a built-in AC to DC power supply.
Running a desktop on straight DC power is not something most of us can accomplish. Laptops, tablets, and phones can be charged with straight DC power.
There are many solar-powered Personal Device Chargers available on the market. It is essential to check for compatibility between the charger and the device to be charged. Not every charger can charge every device.
HVAC
Heating and cooling are some of the biggest expenses homeowners face monthly. Straight Solar air conditioners and heat pumps large enough to heat and cool a home are now available.
These are generally Mini-Split units. If you can use a 120 or 240 AC Volt unit to heat and cool, there is probably a 12, 24, or 48 DC Volt unit that can do the same job.
Pros
- Straight Solar.
- Quiet.
- Heat and Cooling available.
- A single unit can handle a small home.
Cons
- A larger home may require multiple units.
- A little pricey.
- Requires several panels.
- Only heats and cools during daylight hours.
Other Considerations
There are a few other subjects to remember when considering using power straight from a solar array.
The most obvious is that a straight solar application will only operate during daylight hours and at a diminished capacity on hazy or cloudy days.
The other is voltage fluctuations due to panel output.
Sunlight
Even the most efficient solar panel can only produce power in direct sunlight. Power is significantly reduced in the morning and afternoon when the sun is low in the sky.
Full power is not usually available before 9:00 AM and after 4:00 PM. Of course, this varies by latitude and season.
Cloud cover and shade from trees or structures will impact power output.
Voltage Fluctuations
As sun intensity varies, power output from a panel can fluctuate. A 12 volt – 150-watt panel has a Max Volt Output of up to 18 volts.
This high voltage could cause damage to a 12-volt electronic device. It would be wise to incorporate a Voltage Regulator, or a Charge Controller with a LOAD function, into a straight solar application.
Such a device will limit the power going to your device to the proper voltage.
Review
As with any technology, solar power has advantages and disadvantages. An Off-Grid system can employ a bank of batteries and several complex electronic devices to supply power to a home 24 hours a day.
If you do not require 24-hour power, a straight daylight solar system can operate without the batteries and electronics and still provide a lot of functionality.
