IntenseDebate - Sykosys

15 years ago @ Change.gov - Space Solar Power (SSP... · 1 reply · +2 points

I personally do not have these numbers; I'm not an engineer. From what I've heard in my group, the timelines to first KW depend on the scale of the approach. At the very least, $1B, 6-10 years for a working test bed to be developed. There are more costs (launch, ISRU, etc.) that can be factored in, but it depends on the scope of your question.

My personal opinion is that this system will be needed in the long term. The cost will be high, but likely no more so than most of the other options (including nuclear), and most of the estimates I see keep the cost below 7 cents/kwh. The spin-off benefits stand to be many orders of magnitude greater than the investment. My good friend Jim Benson (recently diseased) saw exactly that future as being the next stage in the future of humanity... and is certainly worth a few bucks to achieve. When you consider the vast sums of money to be doled out the financial sector recently, only to be shoved out in 'bonuses', the dollars require to vet this systems seem trivial, considering its potential.

15 years ago @ Change.gov - Space Solar Power (SSP... · 0 replies · +2 points

This would be an good scenario, in theory; right now, NASA's budget is around $20.2 billion. $300 million/year, which would fit well in their budget, or would be a sensible increase.

NASA has a unique capability to do research, but I do not think that they should play a formative role outside of space, as this would muddy their mandate. There are also organizational obstructions that need to be worked out, so that any changes in budget aren't thrown into the void without results. DOE is doing a lot of more traditional research in renewables, which makes sense.

When it comes to SSP and it's alternatives, however, NASA would obviously play a more major role. My concern is that at an institutional level, NASA is reactionary. They don't do much long-term thinking that is needed to ensure that the short term goals are valuable, while keeping towards the long term stuff, and ensuring that it can survive administrations.

15 years ago @ Change.gov - Space Solar Power (SSP... · 0 replies · +1 points

Here, here.

15 years ago @ Change.gov - Space Solar Power (SSP... · 16 replies · +8 points

Great post.

Personally, I do think that laser is a good transmission method - but am concerned that no matter how safe it's made, people will always react as though it can be weaponized. The energy densities are far higher, so it's a much harder case to make with the average Joe. While I have no doubt that the systems can be engineered failsafe, the public simply doesn't have the background to understand why that's so.

Launch technologies are a matter of will. As other posts have pointed out, there are many ways to accomplish the task, and no doubt many that have yet to be flushed out. If the goal is to eventually acquire most of the materials for follow-on sunsats from space resources, it then frees up that launch capability for other uses other than power infrastructure.

15 years ago @ Change.gov - Space Solar Power (SSP... · 0 replies · +2 points

The problem is that the earth has a thermal gradient. Usually it's around 30C/km (86F/3281'). The small units that are available today (heat pumps) are wonderful for moving the heat from your home to the ground or vice versa, for relatively small temperature changes. But to generate power, you need a much larger temperature change, and you need to have enough ambient heat available to replenish that heat removal. Remember the home base system replaces the heat drawn in a seasonal cycle, where the generating systems keep removing it perpetually. So unless you drill deep, you don't get enough of a temperature differential to generate power (via steam or other methods). If you drill deep, you need to have larger volumes for flow and efficiency, which means you need size on the surface. Trailer geothermal systems simply aren't practical unless you happened to be parked in Yellowstone.

Most oil isn't deep enough to have the temperature gradient required. This may be possible in some situations, but not at a large enough scale to be an effective offset. There may be some small scale benefits, but nothing that would be a great help to baseload.

15 years ago @ Change.gov - Space Solar Power (SSP... · 0 replies · +3 points

Sorry, I guess I misunderstood. My point is that Geothermal can provide a percentage of baseload, even all of baseload in some states like Nevada. However, for the rest of the country, it is inadequate, and therefore some other 24/7 power source must be brought to bear.

Nuclear (which is kept in most scenarios) provides 104GW.

What needs to be replaces is non-renewable generating capacity which is 866GW. For the sake of argument, let's say that 1/3 of that is baseload. That means 288GW has to be generated constantly and reliably. If Geothermal takes 40GW as a max, 248GW needs to come from somewhere. And you need to accommodate the complete baseload. Solar is useless an night, and wind is greatly diminished, and there is the storage issue. We need something else that is as capable of non-renewables, and independent of day/night/weather cycles.

Source: http://http://www.eia.doe.gov/cneaf/electricity/epa/epat2p2.html

15 years ago @ Change.gov - Space Solar Power (SSP... · 3 replies · +3 points

I can't disagree with you. Whatever is done must be done with care and consideration. There must be jobs at every level - Obama has talked about infrastructure, and other things that provide many jobs. However, having a project like SSP keeps the PhDs and master trades busy, and can spill over into the private sector. If the high-tech jobs disappear, it will greatly diminish the chances of a sustained recovery when this current crisis is over.

The same goes for timelines; in the very near future, all the 'current' renewable resources must be invested in. But one must also keep investing in the larger scale. Eventually, non-renewables will run out (20/50/75/100 years, pick a number), and when it does, we will need every option at our disposal. Not just for the US, but globally. Those nations that don't have ready access to renewables will go to war looking for it. Like the paper said; a comparable investment as is currently going into fusion (which has been a "will be ready in 50 years" for 50 years) would be appropriate... and doable.

I've always been partial to large catapults.

15 years ago @ Change.gov - Space Solar Power (SSP... · 0 replies · +2 points

What flyingcoyote suggested is, again, one more alternative that should be investigated. One SSP design suggests that it would be more appropriate to beam the SSP energy to balloons/aerial structures/LEO relays, and then send that energy down by tether/laser. This has some advantages, because you have the ability to focus your energy well off of the ground in ways that won't affect the ground nearly as much. May well be room for hybrid systems... I just don't think it's wise to exclude SSP from the mix yet. (And if people are worried about weaponizing microwaves, I can only imagine the reaction to lasers.)

15 years ago @ Change.gov - Space Solar Power (SSP... · 1 reply · +1 points

Again, the windmills are a part of it, but I have my doubts that there will be enough power, and not all Northern States have ample wind resources. There are very few places that _always_ have wind. Like solar, it's is a variable resource. Geothermal is good for baseload, there just isn't enough. Ground solar and wind do not provide baseload, and are not reliable enough for peak, and should only be considered supplementary.

I'm not sure that there is enough mining capacity globally to acquire the lead/lithium/etc. to make the batteries required to overcome that problem. Pumping water uphill is a very inefficient storage method, and also assumes there is enough surplus energy to move enough water... requiring that you have enough height available to actually spin a turbine. (How many people would want a landscape of turbines, and then, on top of that, have to loose a vast area to Hoover Dam structures?)

15 years ago @ Change.gov - Space Solar Power (SSP... · 3 replies · +2 points

The reality is that any crazy nut can do damage if well planned, regardless of the system. Solar panels everywhere aren't much help if the connecting grid fails. Nuclear power plants are vulnerable, so is coal. It would take a very talented nut to hit an SSP in GEO, and the rectenna is easily repaired. I do think it's important to put solar panels on every roof. In the sunny areas of the US, this may do a good part of supplying the power at noon on bright sunny days; but at night and cloudy days, everyone will have to have big and expensive (and toxic to produce) batteries to store the power. If it's cloudy too long, you're out of luck. And those systems are only good for a very conservative consumption profile – not the typical American’s power hungry widgetry. Then you still have to power all the northern states, which can't get enough solar power in winter to do much. Transmission over that distance is a non-starter due to transmission loss.

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