For the last few weeks I've been working on a project to simulate the electrical supply and demand for a Martian colony. I'd really appreciate any feedback people have. The simulator can be found here:https://davedx.github.io/mars-power/The source code is on Github.The motivation behind this was to see what impact dust storms have on PV generation and how PV compares to nuclear (the model uses Kilopower modules here), and what kind of battery strategies could be used to try and ensure generation supply meets demand as often as possible even if a dust storm occurs.Let me know what you think
And as was pointed out in a talk by one of the SX engineers they are looking for something like 500MW for ISRU use at around 500W/m^2 (on Mars surface).
Quote from: redskyforge on 04/24/2018 04:01 pmFor the last few weeks I've been working on a project to simulate the electrical supply and demand for a Martian colony. I'd really appreciate any feedback people have. The simulator can be found here:https://davedx.github.io/mars-power/The source code is on Github.The motivation behind this was to see what impact dust storms have on PV generation and how PV compares to nuclear (the model uses Kilopower modules here), and what kind of battery strategies could be used to try and ensure generation supply meets demand as often as possible even if a dust storm occurs.Let me know what you think Very cool. I guess in your simulation the crew landed on the shore of a previously unknown Martian lake? Sabatier requires water but you only have that and ECLSS in your power consumption budget and no drilling/digging/refining/pumping/etc. for getting the water needed to produce CH4. Likewise no budget for condensing CO2. Also, besides chilling out eating potatoes, what are the members of this colony doing while they watch CH4 being produced? Are they exploring, doing science/research, watching TV, etc? All of these things will require significant power over and above what your model seems to have budgeted.
Quote from: john smith 19 on 04/28/2018 09:53 amAnd as was pointed out in a talk by one of the SX engineers they are looking for something like 500MW for ISRU use at around 500W/m^2 (on Mars surface).I think you'll find it's 500kW.At least near-term.1000 tons of methane combustion energy is 4*10^7J/kg*10^6 = 4*10^13J. A year is 3*10^7s, so a megawatt is the right order of magnitude.With off-the-shelf non thin-film monocrystalline panels, and tesla batteries, you can get 500kW average per BFS cargo mass.At 50% efficiency doing the proper calculation leads to a couple of BFS per synod refuelling capability per BFS cargo. In the ebay powering mars threadYou get three per synod if you can turn off the methane generation during the night.If you are assuming your BFS are going back, and believe the $130/kg number, actual purchase price of the cells is a non-trivial component - 30%.If you can make your solar panels twice as light, but they cost over three times as much, this is not a win.
That's the point of this software... it goes beyond calculations and simulates other events such as dust storms that affect the variability of PV generation. Maybe 500 kWp just isn't enough.
Yeah, even with a good, southerly spot with trackers, to get an average 500kW of power on Mars, you're going to need about a nameplate (i.e. Earth-side at noon) capacity of 4 Megawatts. Probably want more than that for margin and so you don't need as big of a battery or electrolysis plant.
Yeah, even with a good, southerly spot with trackers, to get an average 500kW of power on Mars, you're going to need about a nameplate (i.e. Earth-side at noon) capacity of 4 Megawatts. Probably want more than that for margin and so you don't need as big of a battery or electrolysis plant.Also, pet peave: the Sabatier Reaction doesn't need water, and is technically exothermic so it doesn't need (much) electricity, either. It just needs hydrogen and CO2. It's the production of the hydrogen by electrolysis that requires water and electricity.
Yep. I read this today, it's a great analysis of the requirements for an ISRU propellant plant: http://www.thespacereview.com/article/3479/1It also includes an estimate for the power requirements of robotic water/ice mining, including producing purified water that can be used to break into hydrogen for the Sabatier input. Turns out the mining power requirements are quite high too: 7.5-kilowatt-hour to produce 33kg of water.
Quote from: Robotbeat on 04/28/2018 03:32 pmYeah, even with a good, southerly spot with trackers, to get an average 500kW of power on Mars, you're going to need about a nameplate (i.e. Earth-side at noon) capacity of 4 Megawatts. Probably want more than that for margin and so you don't need as big of a battery or electrolysis plant.Also, pet peave: the Sabatier Reaction doesn't need water, and is technically exothermic so it doesn't need (much) electricity, either. It just needs hydrogen and CO2. It's the production of the hydrogen by electrolysis that requires water and electricity.Yep. I read this today, it's a great analysis of the requirements for an ISRU propellant plant: http://www.thespacereview.com/article/3479/1It also includes an estimate for the power requirements of robotic water/ice mining, including producing purified water that can be used to break into hydrogen for the Sabatier input. Turns out the mining power requirements are quite high too: 7.5-kilowatt-hour to produce 33kg of water.I've made an issue to add this to the simulator.
Quote from: redskyforge on 04/29/2018 02:59 pmQuote from: Robotbeat on 04/28/2018 03:32 pmYeah, even with a good, southerly spot with trackers, to get an average 500kW of power on Mars, you're going to need about a nameplate (i.e. Earth-side at noon) capacity of 4 Megawatts. Probably want more than that for margin and so you don't need as big of a battery or electrolysis plant.Also, pet peave: the Sabatier Reaction doesn't need water, and is technically exothermic so it doesn't need (much) electricity, either. It just needs hydrogen and CO2. It's the production of the hydrogen by electrolysis that requires water and electricity.Yep. I read this today, it's a great analysis of the requirements for an ISRU propellant plant: http://www.thespacereview.com/article/3479/1It also includes an estimate for the power requirements of robotic water/ice mining, including producing purified water that can be used to break into hydrogen for the Sabatier input. Turns out the mining power requirements are quite high too: 7.5-kilowatt-hour to produce 33kg of water.I've made an issue to add this to the simulator. Im going to have to disagree with your characterization of 7.5kWh to produce 33kg of water being “a lot.” The chemical energy of 1kg Of split water is over 4kWh per SINGLE kilogram of water, assuming perfect efficiency. With realistic efficiency, we’re talking more like 7.5kWh per SINGLE kilogram. So electrolysis still requires about 30 times more energy than mining and purifying the water.The energy requirements for mining and purifying the water are basically a rounding error.
SNIPYou get three per synod if you can turn off the methane generation during the night.SNIP
Quote from: speedevil on 04/28/2018 10:16 amSNIPYou get three per synod if you can turn off the methane generation during the night.SNIPElectrolysis, not methane generation. Methane generation can continue as long as there is enough hydrogen left in the buffer. The hydrogen buffer is there to allow steady state operations, reducing catalyst degradation.
It may depend on what the ground is like below the surface. Here in Florida the ground is very sandy, and below that it is limestone. So the "drilling" rig they use for backyard sprinkling systems (between 30 and 100 feet) basically pumps water down under pressure and sucks it back up again. There is not a rotating "bit" like they use up in New England that has to bore through granite.