Comments by Keith Henson Subscribe

On Can Climate Advocates Innovate?

It's not a program the US is likely to do (too much cheap shall gas), but power satellites do scale to more than ten time the current energy use for humans over the whole planet.

And it looks like they could be sell power at a profit for less than coal.

The front end invstment is modest compared to the size of the problem.


September 6, 2015    View Comment    

On Keystone XL Pipeline Opposition: Review of the Major Claims, Relevant Facts, and Most Probable Impacts

Right John, I would prefer to live in an energy rich world.

The problem with the transistion is that the scheme I work on uses up a rather large amount of LNG, in fact, several ship loads a week.

The EROEI is really good, couple of months, but the input of LNG to get off fossil fuels and go to cheaper solar power from space is rather large.

The LNG is used to make hydrogen which fuels Skylon rocket planes hauling parts to LEO.  Natural gas (or fuel oil) powers a microwave transmitter that powers the LEO to GEO run, takes about 4 weeks to lift 15,000 ton cargo stacks.

*If,* and thats a big if, the total cost to GEO can be brought down to $200/kg or less, and the mass of the power plant in space is no more than 6.5 kg/kW, then solar power from space will come in less expensive than electric power from coal.

Reasonable growth rates driven by huge profits can get the carbon growth zero by the early 2030s if this works out.

January 16, 2015    View Comment    

On Keystone XL Pipeline Opposition: Review of the Major Claims, Relevant Facts, and Most Probable Impacts

We should, of course, be getting off all kind of fossil fuel as soon as we can.  But you can't do it by decree or putting road blocks in the way of fuel transportation.

A government that really tried to impose sustanable energy on the population would be out and its policies repudiated by the goverment that replaced it.

What's really needed is what Google called RE < C or renewable energy cheaper than coal.

Coal is around 4 cents per kWh, so the target should be 3 cents per kWh or less.  If you can get it substantially less, you can *make* synthetic crude oil from water and CO2 cheaper than pumping it out of the ground.  With 3 cent power you could upgrade tar sands oil with electrolytic hydrogen.

It's a megascale project, but I think there may be a way to do this.  Maybe even in a timely way.

But rather than look for a solution we get trapped in the politics of this pipeline.


January 16, 2015    View Comment    

On Keystone XL Pipeline Opposition: Review of the Major Claims, Relevant Facts, and Most Probable Impacts

The oil is going to be moved to market one way or another.

Pipelines are far less of a danger than trains.


January 15, 2015    View Comment    

On Power Satellite Progress

October 5, 2014    View Comment    

On Power Satellite Progress

"Can you explain the reasoning behind that number?"


You can find the formula for the levelized cost of electrcity here;

I am assuming $1,600,000 per MW as the initial cost and 10% per year of the cost for maintenance.  Power satellites run supplying base load, here I assume ~91% of the time; it may be higher.

The discount rate is 6.8%, same as the government uses for other sources.  It's put into a spreadsheet here:

The ratio between the $1600/kW cost and the cost that comes out of the formula (~2 cents per kWh) is close enough to 80,000 to one.  Electric power cost is proportional to the cost of a power satellite (or any power source that has no fuel cost) in this ratio for this discount rate and years of service.

If you use the UK government discount rate of 3.5%, then the cost of power is just over 1.5 cents per kWh and the ratio is ~100,000 to one.

October 5, 2014    View Comment    

On Power Satellite Progress

Roger, right on there being a technical dimension.  At the moment I am stuck on the cost and mass of the VASIMR engines needed for the LEO to GEO transfer.

Otherwise, I agree with you about the reasons it is unlikely for the US to do power satellites.  At the moment, the UK is ahead because they are building Skylon.  Japan would like to do virtually anything that doesn't need nuclear reactors.

And, as you mention, China.

October 5, 2014    View Comment    

On Power Satellite Progress

Before you talk about a "1 kw system," you should read the Wikipedia article on space-based solar power and see why 5 GW is the minimum size for a 2.45 GHz microwave power link.

October 5, 2014    View Comment    

On Power Satellite Progress

Roger, the allowable cost for a power satellite is $1.6 B to $2.4 B per GW.  That gives 2-3 cent per kWh power.  The mass of one is 25-30,000 tonnes.  They come in 5 GW lumps, so the cost is $8-12 B each.

Re getting it down, mass in GEO is useful.  Old power satellites can be reprocessed into new ones when and if they ware out.  There are problems with space junk, but they are in getting parts to GEO, not satellites at GEO.  I have an analysis, if you want I can put it up as a google doc.

People have talked about reflecting sunlight on earth based solar farms.  There are problems because the sun is not a point source.  I happen to be interested in solving the big problems, not little stuff involving the ISS.

October 5, 2014    View Comment    

On Power Satellite Progress

Sorry, Roger, I wasn't clear on that point.

2021 is when production at a delivery rate of one a month starts.

2023 just falls out of the financial spreadsheet since there have been enough flights to build up the mass of the first power satellite plus the infrastructure in GEO.

I should send you the spreadsheet.

September 11, 2014    View Comment    

On Why We Need CCS, Part 2: Reactive Climate Change Mitigation

The carbon problem is mostly an energy economics problem because coal is such a cheap way to make electricity, on the order of half the projected end point of solar (zero cost for the PV surface).

So if you want something to displace coal without opposition, it needs to be less expensive.  If you want it to take over in a hurry, then it needs to be much less expensive.

If you can figure out a way to get the cost to lift solar power satellite parts to GEO down to where it is perhaps a third of the total cost, then they clearly win in the energy market.

Cheap enough electric power will also solve the transport fuels problem.  Once cent per kWh power will make $30/bbl synthetic oil, two cent will make $50/bbl.  (Straight forward chemistry and existing plants in the billion dollar class).

So one way to solve the carbon and climate problem (to whatever extent carbon contributes) is to reduce the cost to $100/kg or less for lifting million of tons of power satellite parts to GEO.



May 9, 2014    View Comment    

On Dollar a Gallon Gasoline

Since the 70s, it's always been the case that the microwave intensitiy is less than sunlight.  Birds.

The reason is makes sense is that the amount of energy collected over a year is much higher, the rectenna converts at around 85% as opposed to what you can get from PV, and the thing works 24/7 insteat of about 1/5 of the time for PV.  The rectenna structure is a lot lighter too.  Being mostly open space, you don't have to brace it much against wind.

It's worth reading the Wikipedia article.

April 29, 2014    View Comment