Tuesday, April 19, 2011

Grid based access vs grid independent systems

I started thinking about this entry ages ago when I had an epiphany and I felt that it could be proven that a speed/price/throughput advantage would exist for "fibre" over "wireless". (Conversely, a flexibility and ability to function when the grid is "down", advantage would always exist the other way).

The basis of the proof is basically that any imaginable technology that improves speed over wireless electromagnetic radiation, would be applicable to wired electromagnetic radiation in the same proportion of improvement.

In the case of broadband, at one extreme is Fibre to the Home and the other extreme is Satellite broadband. Wi-Fi is closer to the FTTH side, then there is 3G style wireless broadband that relies on the mobile network which is connected via mainly fibre, and satellite, which can work even if the whole countries internet is down, theoretically. This doesn't really prove that FTTH is worth pursuing, because it is a tenable argument (although I would dispute it) that wireless will improve to the point that it is fast and cheap enough for everything we find important.

Back in Uni, it was proposed that solid state storage improvements were happening faster than hard drive improvements and could overtake them, and although a USB stick is enough for most things, portable hard drives still hold more and are used a lot, the storage advantage of hard drives is constant, due to the solid state improvements being equally applicable to hard drive storage.

Similar grid vs grid independent comparisons are common - road vs helicopter, grid power vs home generators, rail vs aeroplane, piped gas vs cylinders, water tanks vs dam & pipes, private dam storages vs large scale dams for irrigation.

With this in mind, simple goal based arithmetic could decide the balance between grid based and grid independent systems.

For Photo Voltaic electricity generation, I think we have got it backwards, which is why grid parity is not served well with thousands (or millions) of individual installations. If a household is after energy independence, a PV system with a significant amount of battery storage (batteries suitable for an electric car?) is actually very useful and would be a boon for extended power outages (like after Yasi). Because home PV installations are optimised to feed power back into the grid, they are quite useless as independent power sources, compared to diesel generators.

However, if we want PV power to compete with Coal or Gas, we need economies of scale of large scale PV based power stations.

5 comments:

Chris Fellows said...

I think the tricky bit is that the swapover point of efficiency from grid to grid independent systems is different for each of the systems you talk about. My place is better suited to cylinder gas and tank water, but it makes more sense to have a road rather than a helicopter.

I think most of the people who installed home PV systems in our area recently in response to the late state government's "Havabucket O' Money" plan see them as stepping stones to energy independence, as grid prices go up and battery prices go down. I know I do. And I think, if everyone in the neighbourhood did this, it would involve significant savings in infrastructure costs by allowing removal of lots of poles and lines going to very few houses.

Marco said...

I'm not sure I agree with you on either count. In general, country areas will tend to favour grid independent systems. Even roads are necessarily done on the cheap with low capacity (narrow, not fully sealed) and rule out other grid dependent things like buses, taxi and train services to your street. Emergency services like ambulances would be mainly via helicopter.


There is a very false, unsustainable economy with input tariffs for PV systems. Grid prices are going up because private utilities are being forced to pay retail and up for electricity returned to the grid (essentially a Government forced price guarantee for households selling electricity to the utility), while at the same time, more scale efficient large power station proposals are being priced out of the market. This is a vicious spiralling upward of prices, that will only crash once the subsidies become unsustainable. Either the utilities will go bankrupt, or the Government will.

Infrastructure savings tend to be only realisable in infrastructure not needing to be built in the first place. Once it is in place, the cost of keeping it there and the recoverable initial cost is very low. That being said, country areas can gain a lot by having independent generation and storage, while for city dwellers the extra cost is untenable.

Marco said...

I think I am really worked up about the PV "funding". It is the complete opposite of good marconomic policy, as opposed to the NBN, which has divvied up public and private responsibilities beautifully. Setting the input tarriffs *AT ALL* whether temporary or permanent, completely distorts the price signals utilities use both to stay in business and to set investment in power supply.

If the idea was to encourage environmentally friendly energy independence, it should be concentrated on places off the grid as a generator replacement (and to reduce need for infrastructure investments) - ideally with 12V appliances. My parents and brothers houses at west point are a classic case in point. The storage and generation is all in DC. The subsidies available for everybody else are not available to them there because there is no grid. It is a shameful waste of taxpayers money.
It is just a large purchase of power at a price way above the market even for renewables.

It is like as if the government subsidised households to make their own bread which they could sell back to the bread wholesalers at the retail price or above. The wholesalers are not given a choice, the bakers have no recourse and are blamed for the increasing price of bread.

Chris Fellows said...

You still haven't told us what The Economist thinks about the NBN. :P

I reckon subsidies are small beer compared to NIMBYism and the huge cost of replacing aging infrastructure. The subsidies are due to expire a few years down the line, anyway, and I never rule out governments arbitrarily cutting this things early since that is the sort of thing they do.

And, in my case, it is acting to stimulate the depressed 'everything but mining' sectors, as I would just be using my contribution to pay down debt otherwise.

Marco said...

I thought I had mentioned something about the Economist and the NBN. Anyway, I'll mention it again. Since I've formally defined Marconomics, I have noticed that your point about the Economists privatisation obsession is quite true. Perhaps not necessarily for the Example you gave, but they certainly don't get it when it comes to the difference between infrastructure and resources.