DC vs AC for lighting

What you say all makes sense @Theo. I’m certain DC will someday make it into the home on a broader scale but utilities won’t switch to DC. Utilities use A/C because it’s the best method by far for transmission. Edison (DC) and Tesla (AC) fought over their systems but Tesla clearly won that battle. The problem with adding more DC into homes now is that the home’s wiring would need to be replaced and sized for DC. DC requires larger conductors especially when ran for distances longer than 40 feet. The longer a circuit the larger the conductor needs to be. It’s not very practical or economical to wire a home for DC in comparison to AC.

DC generation such as wind and solar are great when they can provide generation but often times there are outages when neither is in supply. Hence we’ll probably always have at least some AC in our homes. Those who can generate solar or wind would be well served to have a grid tie and offset their energy costs. It does require an inverter, which is one of the more expensive components, and requires replacement over the 20 year lifespan about 2 or three times, but it’s still a worthwhile endeavor.

3 Likes

Without a doubt. DC literally sends electrons along the wire, which is an inefficient and relatively slow process, but easy to design electronics for. It’s terrible for any kind of distance, considering Edison envisioned generators on every street corner. :stuck_out_tongue:

1 Like

hmm… I think you are mistaken. In Edison’s time, we did not have cheap electronics to convert DC voltages. That is why conductors needed to be that big. Many see crossing cables are already DC. Actually a system that is designed for AC can move more DC power over its lines. And we are not talking 5V here…

As for generation of power: Of course you can not rely on solar in your neighborhood during the night or wind energy to cool you on a hot day without wind (though solar can). There are many ways of generating power, and with the availability of storage and the possibility to transport energy you can do a whole lot more.

Speed isn’t the issue. DC electrons move at the same speed as AC electrons :wink:

Here is an interesting read to get you informed.

1 Like

There are many complex issues involved when talking about switching from AC to DC. Edison spent a great deal of time trying to find a way for DC transmission which was his downfall in his war with tesla. The first DC electrical utility was built by Thomas Edison in New York. It worked but had some serious limitations, but mostly the transmission over medium to long distances was just not economical. It’s true today that we have all kinds of rectifiers and inverters that we didn’t have in days past. Every electronic device has one that you plug into the wall. It’s an interesting concept, but for each neighborhood to be it’s own generating utility is a bit of a utopian mindset.

I think what we’ll most likely see short term is improved storage solutions for dc generated electricity. Using solar, wind, and geothermal generation methods and better storage cells you could see less dependence on electrical utilities which would reduce demand and supplement supply. Tesla is marketing some of these new battery storage solutions already with the Tesla Power Wall https://www.tesla.com/energy . If everybody started buying electric cars we’d see more solar panel setups with power walls.

2 Likes

It’s no use comparing solutions that were available then, with solutions available now. In those days, AC was the best solution, specifically with the AC motors. We have now evolved to a DC society, where only the power grid is still AC. This is not a sustainable situation.

As you say, ALL storage solutions are based on DC as well. Just think about how many resources you can spare by eliminating the AC/DC transformation. A ballast for example is half the size.

But again, I’m sorry to see that discussions end with hit and run posts and we can not stay on topic. Maybe make a new AC/DC topic? It’s an interesting discussion. We were nominated for the Greentech innovation award with this solution.

2 Likes

You’ve got my brain thinking over the whole idea, but I confess I can’t see your vision of the future. It’s fresh ideas and innovators that end up changing how we think. I’m not against such a transition I just don’t think we’ll see any major changes in my lifetime.

Here’s a project that I’ve followed for a few years now. It’s featured on Bing’s homepage today, which I thought I should share. This power generation facility uses mirrors to reflect and concentrate solar energy onto one small target and is able to generate enormous amount of energy. I think this kind of technology along with other green technologies are going to shape the future of the energy industry.

http://www.solarreserve.com/en/global-projects/csp/crescent-dunes

1 Like

Salt is the secret ingredient in this solar power plant. The system stores energy in super-heated molten salt, so it can deliver power whenever it’s needed, even at night or on cloudy days.

1 Like

It is not something that is going to happen overnight. But already now there are smaller initiatives at self supporting projects, such as bike paths that light themselves at night, and high density industries (such as greenhouses) where DC Solutions are Implemented. At the moment that is only feasible if there is a large demand for power at one location, and alternative energy is available there as well.

You don’t need a full DC infrastructure yet. Using the existing infrastructure though the capacity of the grid can be greatly expanded by starting to transport DC instead of AC.

3 Likes

I love this project and get the pleasure of driving by it all the time when traveling form Vegas to San Diego. And yes, it is truly an inspiring site to see the full scope of human engineering. I agree, projects like these and those on the horizon will have HUGE impacts on the future of energy.

4 Likes

Yep, the variety of different solar generating systems are quite interesting IMO. Photo-voltaic is the most common, but also quite boring. There’s the molten salts, oil-based systems, or just good ol’ fashioned sun-powered steam generators.

1 Like

Good Points @Theo. The examples you spoke of make plenty of sense. When governments and private businesses catch on it could definitely be a win-win for both sides.

2 Likes