Is An Inverter Needed For Solar DC Power? – Converting To AC

Is An Inverter Needed For Solar DC Power? - Converting To AC-Featured Image

You have some solar panels, and you want to know is an inverter needed for solar DC power? Inverters are a great addition to any solar system. Because it means you can do things like use power tools like drills with your solar panels.

It also means that you can power appliances that you would typically use around your home. These include coffee makers, TVs, Computers. Wi-Fi equipment. Blenders and even your refrigerator. Anything that runs off AC power, really.

But what does it all mean, and how does it all work? I hope to answer some of those vexing questions in this post.

Is An Inverter Needed For Solar DC Power?

“So to power DC appliances using solar panels, an AC inverter is not needed. If you want to power AC appliances using solar DC power, an inverter is required. Solar panels produce direct current (DC power) and will power DC-rated appliances via a battery. To convert DC power to alternating current (AC power), an inverter is needed. You can then run appliances that are usually powered from the domestic power grid.”

What Types Of Waveform Are Produced By Inverters

There are two types of inverter: modified sine wave (sometimes known as a quasi sine wave) and pure sine wave. These terms simply relate to the different waveform types and shapes electricity can produce. The different waveforms can be observed on an oscilloscope. Don’t worry, I am not going to bore you to death over this. 

Modified Sine Wave Inverter
Is An Inverter Needed For Solar DC Power? - Modified Sine Wave

Modified sine wave inverters produce a square-looking wave. They will do the job but can produce lots of interference. For instance, when used to power a music system, they can emit a buzz. Some electrical appliances may not work correctly or not run at all, like laptops and TVs.

Having said that, they are cheap and can have higher peak power (surge) ratings. So if you have a restricted budget and feel you can put up with the electrical interference. And the non-running of more sensitive appliances, a modified sine wave inverter might be suitable for you. 

Pure Sine Wave Inverter
Pure Sine Wave Inverter - Waveform

Pure sine wave inverters produce a smooth curved wave. This is the same as your domestic electricity grid makes. You will have noticed that domestic grid electricity produces little interference and will run any appliance. 

Because a pure sine wave inverter does precisely the same thing and produces an identical wave. You can rest assured there will be no buzzing while listening to your favorite tunes. Or your TV will work when the next episode of the program you are hooked on is transmitted.

This is a video from The Engineering Mindset Power Inverters Explained – How do they work working principle IGBT

What Does Inverter Continuous Power And Peak Power (Surge) Mean?

These are two different terms related to an inverter’s wattage.

Continuous Power

Continuous power is a description of the amount of wattage the inverter will handle at any given time. All appliances described technically as the load has a wattage rating.

A TV, for example, can have a 65-watt rating and a powerful hairdryer 1800w. A Fan assisted oven 2500w, a kettle 2300w, a toaster 1200w, and a microwave 800w.

On the face of it, a 3000w inverter will continuously run any of these appliances individually. But what if you wanted to run them all at the same time? The wattage of each appliance becomes incremental. So to run all of the above devices continuously would require an inverter that could handle 8665w.

I know it would be a rare occasion to have this many high-wattage appliances running simultaneously. But when you add other devices like the fridge, lights, and washing machine into the equation. You can see a stand-alone house solar power installation is going to need a very large inverter. 

Is An Inverter Needed For Solar DC Power?
Peak Power (Surge)

The term peak power relates to the inverter’s total maximum power output. What do I mean by that? If an inverter has a continuous output rating of 3000w, it will have a peak power rating of 6000w. This does not mean it will handle 6000w of constant power.

It means it will operate for a very short period of time (usually 5 seconds max) up to 6000w. This is because many electrical appliances use more watts at startup, usually for a second or 2. This is known as the surge. So, for instance, say your 3000 inverter is running at 75% continuous power; that’s 2250w.

You then turn another appliance on that has higher wattage surge momentarily on startup. Taking the inverters continuous output capacity over 3000w. This is when the peak power feature will kick in, and the inverter will temporarily run at a higher capacity. 

Examples of appliances that have a high surge on startup because they use motors, transformers, or capacitors are;

  • Air Conditioners
  • Water Pumps
  • Refrigerators
  • Vacuums
  • Power Tools
  • Camera Flashes

What Size Inverters Are Available For Converting Solar DC Power?

There are 3 sizes of inverter for converting solar DC power to AC they are;

  • Small
  • Medium 
  • Large

I know you thought sizing descriptions might be a bit more complicated than that, didn’t you?

Small Inverter

Small inverters are usually used to describe units that produce 3000 watts of continuous power or less. They are ideal for use in portable applications where they are powered by a 12-volt battery. 

They are lightweight and can be positioned on a shelf or desk. Usually, if the solar installation is in an outhouse like a shed, garage, or workshop. If being used in a recreational vehicle, they can be mounted in the battery compartment. It should be noted that adequate ventilation is required in a confined space.

Medium Inverters

House Inverter DC to AC Inverter

These are inverters producing 4000 Watts (4Kw) to 9000 (9Kw) watts of continuous power. They can be used for mobile, outhouse, home, and industrial stand-alone or grid-tied applications. But are heavier and need a secure mounting.

Large Inverters

These inverters produce 10,000 watts (10Kw) of continuous power and can be used for much larger applications. Manly in substantial houses and industrial and office environments and need to be bolted to the floor.

What Is The Difference Between Stand Alone and Grid-Tie Inverters

There can be some confusion between these two very different types of inverters. After all, you just want to use an inverter to generate AC power from your DC solar system.

Stand Alone Inverters

As I have mentioned earlier, a stand-alone AC inverter is designed for use with mobile applications. Or solar installations to smaller buildings where the inverter draws its power from a battery. 

These inverters can be used in recreational vehicles, cars, campers, boats, and trailers. In the case of cars, they can be hooked up to the DC cig port to provide AC power. For RV’s etc., they can be hooked up to the house battery bank. The same goes for solar installations to smaller buildings like a cabin, garage, workshop, or tiny building.

Varta Lead Acid Battery

If you want to know more about stand-alone inverters and how they work with solar panels. You can read about that here;

Related >>>>>>>>>> What size inverter do I need for a 100-watt solar panel?

Inverter/Chargers

This is what AltE Store has to say about Inverter/Chargers

Another common use for an inverter/charger is in a boat or an RV, where you have an inverter/charger charging the battery bank from shore power or a generator, and the inverter converting the DC power to run your AC loads. (Source: altestore.com)

Grid-Tie Inverters

A grid-tie inverter is used in a residential solar installation; it doesn’t get its power from batteries. It gets its power directly from the solar panels installed at home. When the solar panels produce DC electricity, the inverter converts it to AC for use directly in your home.

When the solar panels are not producing electricity, the inverter switches back to grid power, at night, for instance. 

Hybrid Inverters

EnergySage says;

A hybrid inverter, otherwise known as a hybrid grid-tied inverter or a battery-based inverter, combines two separate components–a solar inverter and a battery inverter–into a single piece of equipment. (Source; energysage.com)

What that means is that the solar panels fitted to your house when attached to a hybrid inverter. Can provide direct AC power for immediate consumption. And charge batteries for storage for later use, such as at night. This means you would be even less reliant on domestic mains grid power.

My Closing Thoughts

If you asked the question because you wanted to know if you needed an inverter to power DC appliances. I hope I have successfully given you the answer that you do not need an inverter.

If you are asking this question because you wanted to know if you needed an inverter. Because you want to convert DC solar power to AC grid current to run domestic appliances. You now know the answer is most definitely yes.

I also hope I have managed to debug some of the terminologies for you. And point you in the right direction concerning the type of inverter that might possibly meet your needs.

If you would like to know more, I have written a review about various stand-alone inverters. You can take a look at it here:

I hope you enjoyed this post and have found it helpful. If you have any questions about the type of inverter needed for DC solar power. Or want to leave your own personal review, please feel free to leave a comment below.

Spread The Solar Love

4 Comments on “Is An Inverter Needed For Solar DC Power? – Converting To AC”

  1. Ill be honest I have always wondered if an Inverter is needed for Solar DC power and after reading this article you have answered a lot of questions that have come up in my head, like being able to use power tools with a Solar DC power. Im new to the solar world as I just bought my first solar panel last year and still dont quiet know everything about how it works but its very good to know that I can use the Solar DC power for things like my power tools while using it. Great Article very Informative. 

    1. Hi Page

      Unfortunately you can’t use power tools with DC power. They run on AC power so you need an inverter to convert the DC produced by the solar panels to AC to power domestic appliances. DC rated appliances are usually associated with camping and RV’s and other off-grid applications. 

      I hope I have cleared that up for you if you have any other questions please do not hesitate to ask 

      Regards

      Steve 

  2. This is a very comprehensive post on inverters, a topic that is quite technical and complicated for many people. So how do I know whether a product uses AC or DC? Would it be somewhere on the product or in the technical specification? 

    We are looking at getting mobile solar panels to be used with a RV, so it would need to run the small fridge, and possibly a water pump. So it sounds as if we will need an inverter, but then what size do we need? Is there a standard ration of how many panels can be used with an inverter? Thanks you. 

    1. Ok you would need  AC power for any appliance that normally runs from your household electricity sockets. Such as a kettle or fridge freezer or power tools and you only need an inverter to run those types of appliances.

      DC power is what solar panels produce to charge DC batteries. So you would buy DC appliances to run off the DC batteries. These are usually found in RV’s and camping. So you can buy a DC TV, or a water pump or kettle for instance that will run off a DC battery.

      There isn’t a standard number of solar panels you need for an inverter. Choosing an inerter size to use starts with what wattage AC appliances you want to power. This would take up a whole new post. If you have any further questions please do not hesitate to ask

      Regards

      Steve

Leave a Reply

Your email address will not be published.