#205 – Solar Factories and HVDC Lines – Pollent Power Pushing



Image is courtesy of ABB


  1. says

    50%, yeah. Peak value at one point of time. NOT average. “We” are actually building new coal-fired power-plants and due to the fucked up way the market works here, “we” are exporting electricity as well. All paid for by massive subsidies. How much do you guys pay per kWh? I pay 26¢ (€).

  2. rasz_pl says

    Fear and Loathing in Las Vegas by Chris Gammell!

    Read about ze Germans and its hilarious, the more ‘green’ energy they produce, the more expensive it gets. To the point of them having to shut down modern natural gas plants.
    This is not going to end well, ‘renewable’ doesnt work without base load plants, and subsidies basically kill them.

    • says

      In Engineering, one short-hand method we are taught is to take a problem to its limit. The answer at the limit will tell you something about the trend.

      By that method ‘renewable’ is the only thing that will work in the end. by that method non-green energy (coal, oil) is the only thing that will not work in the end. What we should question is how to get from A to B.

      I don’t know a lot about these short term political and economic problems (subsidies, taxes and such). One thing I believe is that people tend to be biased and we humans are not good at noticing our own bias. I believe that politicians are not often good at engineering.

  3. SeanB says

    I will add as well the modern plants rely on optical powering of the high voltage switch assemblies, with almost all of them having a large fibre optic cable to provide the control via a laser to trigger the thousands of SCR units in the assembly. You basically have 2 choices in the power device, lower power uses IGBT devices, but high power almost universally uses SCR switches, with a single bank having thousands of smaller devices in a series parallel connection, and a large number of passive components like inductors, capacitors and varistors as well, They are used to filter and to allow the active devices to be switched off and to control the voltage and power levels.

    The simple reason they use DC is that you only need a single wire in most cases, or 2 wires, to have a high power 3 phase link that can often transfer power in both directions as needed. High voltage DC allows more power to be carried, as the insulators are run at the DC voltage, whereas on a standard AC line you have to limit the voltage to 70% of that, as you have a RMS voltage. This extra 30% increase in voltage means a lot more power transfer, and you can also run the current higher as the end stations can do voltage compensation on a cycle by cycle basis without wear. Using one or 2 conductors with a ground return mat also reduces the cost of the line.

    At high power the savings in line material and insulators will cover the extra cost at the end stations for the inverters and associated control and structures. As this cost is maintenance wise almost zero extra cost it pays for itself at the initial design stage. Line wise you save having less insulators to clean and less lines to maintain. You also have less loss to capacitive loading, and this capacitance actually helps with voltage regulation.

  4. Chris says

    Dave’s right. Every idea does not have an equal chance of success.

    You don’t get an award for participating. You get it when you win.

  5. Chris says

    Listening from Wellington, NZ
    Most of our power is supplied via an HVDC link from the Benmore Dam in the South Island.

  6. says

    That “Diagrammer” machine is very interesting. I love these kinds of manually operated “automation” machines. There’s an old exhibit in the Derby Industrial Museum of a machine that can take a pair of 2D mechanical drawings and produces a perspective drawing of the article. Lots of dials, lots of switches and pulleys and awesomeness.

    I bet there are a lot of old machines that are decaying in museums which nobody knows how to operate or restore. I offered to organise a team to attempt a complete restoration of the machine at the museum, but they weren’t interested. I would have done it for free too. :(

  7. John says

    Transmission lines are never copper, they are ALSCR, aluminum steel core reinforced. DC transmission lines are pretty much for LONG distances only, no substations tapped off along the line as AC lines. Just one converter station on both ends.

  8. Pedro Gomes says

    I, Chris and Dave

    Portugal got there first, with 58.3% of the country’s electricity generation in 2013 form Renewable energy.