Solar panels will be rolled onto Swiss railway tracks ‘like a carpet’
www.euronews.com
After long delays, the removable PV system will finally be tested on a western track next spring.

I’m all for putting solar panels all over the place, but won’t these get dusty and oily and need loads of cleaning after trains pass over?

Also, costing €623,000 over three years sounds rather expensive for just 100m (although that roughly equates to 11KW).

  • golli@lemm.ee
    0·
    11 days ago

    I’ll try to track it down, but am kind of having a hard time finding their methology for those stats. Which ones do you think are unsure about? the 20MWh/year/hectare biomass, 800 MWh/year/hectare solar or the energy loss through stroage with batteries/hydrogen? Or something else?

    I’ll try a bit further to find their specific methology when i find the time. But for the solar part i also did a quick google search and found for example this paper. To quote from their conclusion:

    Based on empirical observations drawn from a large, nearly complete sample of utility-scale PV plants built in the United States through 2019, we find that both power and energy density have increased significantly over the past decade. Modelers and analysts, policymakers and regulators, and others who continue to rely on outdated benchmarks from the last comprehensive U.S.-based assessment of power and energy density conducted nearly a decade ago [6] will, therefore, significantly overstate the land requirements, and by extension perhaps also the land-use impacts, of utility-scale PV.

    Updated benchmarks as of 2019 established by this study are as follows.

    • Power density: 0.35 MWDC/acre (0.87 MWDC/hectare) for fixed-tilt and 0.24 MWDC/acre (0.59 MWDC/hectare) for tracking plants.
    • Energy density: 447 MWh/year/acre (1.10 GWh/year/ hectare) for fixed-tilt and 394 MWh/year/acre (0.97 GWh/year/hectare) for tracking plants.

    It is about the US and not Germany, but i wouldn’t expect there to be massive differences. If we assume that Germany has slightly worse conditions for solar, then 800MWh/year/hectare seem in the right ballpark.

    • Tobberone@lemm.ee
      0·
      10 days ago

      It was more the relation between them (40x) that struck me as bigger than I expected given the relative performance between photovoltaic and photosynthetic efficiency.

      If they compare 1-year crops for human consumption, there will be a lot of tilling, sowing etc. but then we compare two different use cases with different purposes.

      Wood intended for burning for district heating, where the heat is taken care of with high efficiency, would be an energy usage more akin to electricity. In that case I would expect the harvesting and transportation part to be different.

      As a swede, energy usage in the winter is warm at heart which is something that is hard to compare and muddles the numbers. In Dec-Jan energy (kWh) output from solar is at best 9-10% of their peak output during summer at my latitudes, (further north, this goes towards zero as there is no sunlight in winter), so with that in mind, the stored 20MWh/hectare, available round the clock, looks apetizing until we find a better solution to store energy.