Evslin: Build the grid back better – switch to DC

by Tom Evslin

Let’s really Build the electric grid Back Better. That means converting to direct current.

There’s no argument that our electric grid needs to be rebuilt. Some of it, like the transmission lines that sparked the California fires, is dangerously past its use by date. Much of it, like the lines radiating out from the site of the former Vermont Yankee nuclear plant, are in the wrong place. The design is centralized as a relic of the days before advanced electronics and communications made decentralization a more resilient and cheaper option. Almost all of it carries alternating current (AC) as result of an argument Nicholas Tesla won over Thomas Edison a century ago. Most important, the grid is not ready for the loads we will put on it as we continue to electrify. It is also not reliable enough to be the sole source of energy for transportation and heating.

Times have changed. All the electronics in our houses use direct (DC) and not alternating current; that’s why they are plugged into our AC outlets through the ubiquitous converter bricks. Almost all energy efficient appliances use direct drive motors and convert AC to DC internally. LED light bulbs are better with DC. Water heaters don’t care.


The illustration above is from a report by the American Council for an Energy-Efficient Economy (ACEEE) The report estimates that at least 10% of the energy coming into a house is lost in conversion from AC to DC. The number is much higher if a storage battery or an electric car is also being charged. The number gets higher each time a rechargeable tool replaces a gasoline-powered predecessor.

All solar panels generate direct current. All batteries are charged with direct current. But, if you have solar panels and battery backup today, the output from the solar panels is converted to AC by an expensive piece of equipment and at a significant energy loss; then, at the battery, the AC is converted back to the DC the battery needs by another expensive piece of equipment and more energy is squandered. These inefficient systems exist today because the transition from AC to DC had been unplanned; that’s no one’s fault.

But now we have a chance to build back better with the money already appropriated in the 1.2 trillion dollar bipartisan infrastructure bill.

Fortunately we have time. The last great stimulus bill in the Obama administration was a jobs bill. We had to put people to work right now right now even though we didn’t have constructive “shovel ready” jobs for them. Unemployment was very high. That was then and this is now. We have a shortage of people to do what we were doing before the pandemic. We can plan and design and then really build back better while we’re training the workforce we’ll need.

These are some of the rules we need:

  1. Any new transmission line and any line which is substantially rebuilt with the federal money must be DC. There will be a transitional cost of equipment to convert to AC where local sub-transmission or distribution is still AC. Think of these convertors as scaffolding for building back better. After all grids are DC, we won’t need them anymore.
  2. Any new distribution line any distribution which is substantially redone with the federal money must be DC. Again there is a transition cost to convert to AC at houses which still need that.
  3. Building codes should be amended (a local and state job) to permit and encourage DC and hybrid houses as in the diagram below (also from ACEEE).

Once the distribution system is switched to DC, the inverter at the entrance to the house is no longer needed.

  1. After a transition period no grant money or subsidy of any kind should go to equipment for converting from DC to AC as part of solar or wind turbine installations or from AC to DC for battery installations.

5.Give consideration to going underground for new and rebuilt parts of the grids for reliability reasons (and to prevent forest fires). There are less problems in burying DC lines than AC lines.

  1. Take advantage of the rebuilding of highways to bury electrical (and broadband) conduits as well as drainage.

America and Americans will have a huge advantage if we are the first major country to go all DC. Our energy costs will be lower as will emissions from generating electricity. Electricity will be more economical and reliable enough to replace much fossil fuel. The money’s already been appropriated.  We can build back BETTER.

Categories: Commentary

9 replies »

  1. Globilist. Worked for Billy-Goat Gates. Made a fortune and now wants to dictate (and profit from) how the rest of us live from here on…these are the type men and women who appoint themselves the ruling class

  2. Someone wants to revisit the 140-year-old “battle of the currents”? As Nikola Tesla’s genius determined back then, AC is the only option for regional and local transmission. There are new technologies for high voltage DC for long range transmission as was/is proposed for a corridor running from HydroQuebec, under Lake Champlain and along the Hudson to supply the NYC area
    but it is totally impractical to use DC throughout the grid as a whole. AC allows the easy conversion to different voltages. There are electronic devices known as DC-DC convertors but they are typically for low-current applications and have the same kind of efficiency problems as our ubiquitous AC-DC convertors plugged into our walls. The biggest argument against Edison’s DC system is that it would have required power plants to be located every few miles. We do essentially have that now with PV panels spread out across the land but if we are still to rely on large producers for our base power, the only practical way to distribute that power is with AC at high voltages. Let’s hear from some electrical engineers on this before we reinvent the wheel.

    • Thank you ! While some people would like to switch back to horse and buggy, i personally prefer modern technology.

  3. Re: “These are some of the rules we need:”

    Here they are again… more ‘rules’. When will Milton Freidman’s common sense perspectives reach these folks? Go ahead and consider Mr. Evslin’s ‘rules’. But in the final analysis, trust the market. Get out of the way.

    “One of the great mistakes is to judge policies and programs by their intentions rather than their results.”

    “Most of the energy of political work is devoted to correcting the effects of mismanagement of government.”

    “A major source of objection to a free economy is precisely that it … gives people what they want instead of what a particular group thinks they ought to want. Underlying most arguments against the free market is a lack of belief in freedom itself.”

    Again – The first lesson to be learned is that no oligarchy in the world has ever demonstrated the expertise to successfully manipulate the economy without increasing the aspect of unintended consequences.

    Praemonitus praemunitus.

  4. Evslin nails it again, with a complete rework of the nation’s electrical generation, transmission, distribution and utilization system. Just awesome how some can spend other people’s money so well. Like a teenager or a liberal- Evslin must think money grows on trees in the backyard.
    As Evslin states in his “required rules”- think of this idea as scaffolding for build back better-
    Ideas that make a certain few immeasurable rich and powerful while making electric power scarce and expensive for us mere peons.
    If DC current was economically feasible and viable, the USA would have switched long ago.
    Markets, not government need to establish how things work Mr. Evslin. Can you reply with something the government can do better and with less cost than free enterprise?

  5. That would be the most ridiculous way to build back better you could possibly imagine. You could spend trillions of dollars DCifying the grid and you’d maybe save 5% ongoing if you’re lucky. Maybe it pays off in 1000 years? This is the kind of BS big-government central plan you get with Democrat New Green Deal thinking. Let’s connect every US city with a hyperloop while we’re at it. Utterly insane.

  6. Who let thus dog out? Shees, the losses in DC transmission are prohibitively massive.
    This person flunks.

  7. What Evslin fails to understand or recognize is that transmission of electric power has resistive losses meaning that resistance in the lines/wires causes heating due to the electric current drawn and results in progressively lower voltage (voltage drop) from source to destination. With AC distribution that loss in voltage restored with transformers to provide all customers with a reasonably similar service voltage. A DC system does not intrinsically have the step-up capability that AC does. Voltage step-up or restoration can be done electronically with DC to DC inverters but it is more expensive and the process consumes power. The other factor with a DC only system is that any conversions, including the popular solar panel to storage battery, use semiconductors which have a finite lifetime and a recycling cost.

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