plantyhamchuk: Let’s talk about energy - coal, solar, inefficiencies and waste. Okay, this is

plantyhamchuk:Let’s talk about energy - coal, solar, inefficiencies and waste.Okay, this is an old chart from 2004, involving the energy flow of various energy resources in the USA. This chart has blown my mind and you’ll have to read all the little tiny writing to understand why it is so profound. Let’s look at it for a minute:The input on the left side is variety of things. The dark brown in the upper left is coal, which is used to power steam plants. The thin light blue arrow just under the brown is natural gas, which is also used to power steam plants. The itty bitty section green is petroleum and biomass. Cutting in, the red is nuclear, the yellow is hydroelectric, and there’s a tiny sliver of geothermal/wind. These all involve turbines, converting energy from one type to another.These make up the two arrows that go to the right.The upper arrow shows what is lost during converting energy from one state to another and transmission of the energy to the home, that’s the 6.58 quadrillion BTUs. The lower arrow of 4.40 quad BTUs? That’s what actually makes it into your home. Like, that’s fucking amazing. Amazingly horrible. The lower large blue arrow on the left is again, natural gas. You’ll note it doesn’t have the losses of the ones above, it is used primarily for space heating (3.46 quad BTUs), water heating (1.13 quad BTUs), and a negligible amount for actually cooking.The dark gray is Petroleum Distillate (1.02 quad BTUs) and Petroleum LPG (0.55 quad BTUs) are mostly for space heating (1.20 quad BTUs).The green at the very bottom as Wood/Solar at 0.41 quad BTUs, and it is primarily used for space and water heating.Let’s look at just how coal is used anyway:So this is more itty bitty writing, but #8 is the coal conveyor belt. You burn the coal to create hot steam, which turns the turbines, which creates electricity. You’re converting chemical energy (coal), turn it into mechanical energy (turning the turbines), which then converts it into electrical energy. As you know from the chart above, only 40% of the original energy makes it to your home.This is absurd, because the #1 use for electrical energy in the home is to heat it, so you turn that electrical energy back into thermal energy. It’s just crazy wasteful af all around. Much of the US grid - and many other countries - still runs on coal.“When measuring energy used to provide thermal or visual comfort, site energy is the most useful measurement. But when measuring total energy usage to determine environmental impacts, the source energy is the more accurate measurement.“ This means to not just look at that 40% that makes it into the home, because you’re not seeing the big picture that way.Here’s another more recent graphic. It incorporates more information, this isn’t just residential usage (top pink square) but also commercial, industrial, and transportation. Once again though, you can see the immense losses in the system. The light gray on the right - “rejected energy” - is entirely wasted. The dark gray on the bottom right is “energy services”, or what was actually used. You will note that coal usage is way down (dark gray on left) compared to natural gas (light blue). It also includes petroleum (dark green at bottom) for transportation that again, wasn’t accounted for above.SOLAR - Photovoltaic (PV), Passive Design, Thermal“ 1 kWh of site electricity from a solar panel on the building’s roof is equal to 1 kWh of source energy, because the solar panel itself is the source. “So this means solar is even more awesome than people might have realized, in light of all that waste and inefficiency mentioned above. If you slap some solar panels on a structure and use it to directly power that structure? You’re not looking at the kind of waste that comes when we try to burn shit to turn turbines a la steam.However, most people are not trying to heat their houses with PV solar. At least not yet anyway, due to cost. One 1500 hundred watt space heater would cost $3200 for a basic solar setup to power it.What to do? Well, passive solar design allows you to capture thermal energy directly from the sun in winter, and avoid it in summer, so it allows you to work around the #1 use of energy in the home. Thermal solar allows you to heat fluids, which can be used to heat your water (or at least supplement it), and for people who want to get fancy and install tubing in their floors, you can also help heat your home that way. The fantastic page I grabbed most of these pictures and some text from is here and I recommend checking it out if this interested you in any way. -- source link

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