[Shaved Monkey]

The electricity grid is here to stay
Home battery uptake points to emergence of 'virtual power plant'
The ability to connect the batteries in a network means they could be called on by a power grid operator when electricity demand is high or during an outage elsewhere in the system.

Simon Hackett, technology entrepreneur and executive chairman of home-grown battery developer Redflow, predicts that in just three to five years, grid operators will start to offer customers who own home storage systems the opportunity to get paid to send energy back into the grid when the system needs it.

"The way this is heading is a world where if there's a few thousand of these in a city, collectively you've actually got a power generator," Hackett says. "So rather than spinning up a gas-fired peaking plant somewhere, you can set the inverter in reverse and push the energy straight back into the grid on demand."

Locally, intelligent control systems and software being being developed by start-ups such as Redback Technologies in Queensland and Reposit Power in the ACT that are specifically aimed at allowing households to send power back into the grid when needed.

The concept underscores the value of staying connected to the grid.

Households with rooftop solar and batteries can avoid the huge extra expense of back-up power and extra storage capacity to be totally self-sufficient, while grid operators can avoid extra investment in system capacity that may only be called on a couple of times a year.

Going one step further, Hackett points to the potential for creative solutions on batteries that could also solve state governments' heavy forward liability for generous historical solar feed-in tariffs.
A voluntary exchange of those tariffs for a battery installed by the government, for example, could save taxpayer funds while inserting valuable, externally controllable power systems into the new smart grid.

http://www.afr.com/business/energy/elec ... 331-gnuxao

[vtsnowedin]

The electricity grid is here to stay
Home battery uptake points to emergence of 'virtual power plant'
The ability to connect the batteries in a network means they could be called on by a power grid operator when electricity demand is high or during an outage elsewhere in the system.

Simon Hackett, technology entrepreneur and executive chairman of home-grown battery developer Redflow, predicts that in just three to five years, grid operators will start to offer customers who own home storage systems the opportunity to get paid to send energy back into the grid when the system needs it.

"The way this is heading is a world where if there's a few thousand of these in a city, collectively you've actually got a power generator," Hackett says. "So rather than spinning up a gas-fired peaking plant somewhere, you can set the inverter in reverse and push the energy straight back into the grid on demand."

Locally, intelligent control systems and software being being developed by start-ups such as Redback Technologies in Queensland and Reposit Power in the ACT that are specifically aimed at allowing households to send power back into the grid when needed.

The concept underscores the value of staying connected to the grid.

Households with rooftop solar and batteries can avoid the huge extra expense of back-up power and extra storage capacity to be totally self-sufficient, while grid operators can avoid extra investment in system capacity that may only be called on a couple of times a year.

Going one step further, Hackett points to the potential for creative solutions on batteries that could also solve state governments' heavy forward liability for generous historical solar feed-in tariffs.
A voluntary exchange of those tariffs for a battery installed by the government, for example, could save taxpayer funds while inserting valuable, externally controllable power systems into the new smart grid.

http://www.afr.com/business/energy/elec ... 331-gnuxao

Is there enough lead and other materials to make that many large batteries?

[dohboi]

Some hydro allows you to have 'virtual' batteries. When the wind is blowing and/or the sun is shining, don't let as much (or any) water through, then when you have a lull in wind/sun, you let out that extra water for power generation. I'm sure people are working on other tactics that relatively cheaply store energy without resorting to lead (or other types of) batteries. Compressed air seems to come to mind, but I haven't kept up with those technologies.

But again, managing load is crucial, it seems to me.

[vtsnowedin]

Some hydro allows you to have 'virtual' batteries. When the wind is blowing and/or the sun is shining, don't let as much (or any) water through, then when you have a lull in wind/sun, you let out that extra water for power generation. I'm sure people are working on other tactics that relatively cheaply store energy without resorting to lead (or other types of) batteries. Compressed air seems to come to mind, but I haven't kept up with those technologies.

But again, managing load is crucial, it seems to me.

Yes I'm aware of those strategies and possibilities but again we have to consider is there "ENOUGH" of them to meet the need. Enough is the question.

[dohboi]

"to meet the need"

I would say, "What is the need" is the question. As well as "When is the need."

I know that these are not the traditional questions usually asked in the past in the area of energy generation, but they simply must be central to the discussion in the ever more limited world going forward.

[dolanbaker]

Some hydro allows you to have 'virtual' batteries. When the wind is blowing and/or the sun is shining, don't let as much (or any) water through, then when you have a lull in wind/sun, you let out that extra water for power generation. I'm sure people are working on other tactics that relatively cheaply store energy without resorting to lead (or other types of) batteries. Compressed air seems to come to mind, but I haven't kept up with those technologies.

But again, managing load is crucial, it seems to me.

Yes I'm aware of those strategies and possibilities but again we have to consider is there "ENOUGH" of them to meet the need. Enough is the question.

Tidal power is the most reliable of all the renewables, it is also one of the most expensive to implement. Once installed it has the longest life expectancy.

The use of tidal lagoons together with tidal piers & turbines could potentially provide all the electrical power a country with a large coastline could ever need. The tidal lagoons would fill & drain out of phase with the tide, thus providing power when the tide is static.

Of course, such a system would be totally dependent on a centralised power distribution system, even more so for landlocked regions & countries.

Tidal power could become the "baseload" to replace fossil fuel for power generation in many parts of the world.

[vtsnowedin]

Some hydro allows you to have 'virtual' batteries. When the wind is blowing and/or the sun is shining, don't let as much (or any) water through, then when you have a lull in wind/sun, you let out that extra water for power generation. I'm sure people are working on other tactics that relatively cheaply store energy without resorting to lead (or other types of) batteries. Compressed air seems to come to mind, but I haven't kept up with those technologies.

But again, managing load is crucial, it seems to me.

Yes I'm aware of those strategies and possibilities but again we have to consider is there "ENOUGH" of them to meet the need. Enough is the question.

Tidal power is the most reliable of all the renewables, it is also one of the most expensive to implement. Once installed it has the longest life expectancy.

The use of tidal lagoons together with tidal piers & turbines could potentially provide all the electrical power a country with a large coastline could ever need. The tidal lagoons would fill & drain out of phase with the tide, thus providing power when the tide is static.

Of course, such a system would be totally dependent on a centralised power distribution system, even more so for landlocked regions & countries.

Tidal power could become the "baseload" to replace fossil fuel for power generation in many parts of the world.

Well you can't build a tide basin in Boston harbor or the white cliffs of Dover or at Malibu beach so where are you going to find "Enough" suitable sites?
There is the one big one in France that has been working for years but if there were a lot of good sites there would be more of them by now.
Tidal power dose have some potential. I'd start by tethering a turbine to every off shore wind towers foundation that is sighted in a tide flow to use the wind turbines distribution lines. But there are a limited number of off shore wind turbines that have sufficient tide flow going past them.
Take what we can get where we can get it but again I think the problem is our needs or demand if you prefer far exceeds our ability to build carbon free alternative power sources.

[dolanbaker]

You can build tidal lagoons along just about any coast that has a decent tidal range. You can also build tidal barrages that run perpendicular to the coast for about 40km and place turbines in it as the tidal flow is mostly parallel to the coast.

Everything is possible, but is much easier if we transition to a slower less energy intensive BAU first.

This video demonstrates what I have in mind.

https://www.youtube.com/watch?v=W7PTxoW66dM

[vtsnowedin]

You can build tidal lagoons along just about any coast that has a decent tidal range. You can also build tidal barrages that run perpendicular to the coast for about 40km and place turbines in it as the tidal flow is mostly parallel to the coast.

Everything is possible, but is much easier if we transition to a slower less energy intensive BAU first.

This video demonstrates what I have in mind.

https://www.youtube.com/watch?v=W7PTxoW66dM

And the video shows two areas with the required shallow flat bottomed seas with parallel tide flow. The Netherlands and the South China sea. They also state a goal for China of fifteen percent of their energy from renewables including these tide projects by 2025. That might be possible but it is that other eighty-five percent I'm talking about.

[dolanbaker]

As the video is showcasing a joint Nederlands & China venture, it's no surprise that it's concentrating on those areas.
Most of the coast of the UK & Ireland is suitable for such schemes and probably much of the global coastline as well.
Those that don't have perpendicular tidal currents can still construct parallel barrages or use the free-standing units.

The 15% I suspect is for this phase of the project, the question is "how much coastline is included to make this 15% target achievable?" I just cannot see China having their entire coastline covered by tidal power schemes in ten years.

[vtsnowedin]

As the video is showcasing a joint Nederlands & China venture, it's no surprise that it's concentrating on those areas.
Most of the coast of the UK & Ireland is suitable for such schemes and probably much of the global coastline as well.
Those that don't have perpendicular tidal currents can still construct parallel barrages or use the free-standing units.

The 15% I suspect is for this phase of the project, the question is "how much coastline is included to make this 15% target achievable?" I just cannot see China having their entire coastline covered by tidal power schemes in ten years.

I'd want to take a long careful look at the projected costs per KWH over the life of the project before i got too excited about it. Building structures to withstand storm level waves is an expensive proposition.

[dolanbaker]

Expensive, yes of course it is, all forms of energy extraction are expensive, just look at how much money was thrown at the fracking industry. And the result was a flash in the pan!
At least with most renewables it'll be more of a long lasting glow, which is why investors are reluctant to go there, too long to wait for a return.
It's the cost of installing the infrastructure required to support such schemes that will probably stop their development.

[dohboi]

I haven't looked into tidal power recently. My impression from earlier explorations was that it was too expensive, and impractical in most locations for other reasons as well.

But it seems possible to me that such mechanisms could, like reservoirs behind dams, also act as 'virtual batteries,' which might make them a bit more attractive, perhaps?

[vtsnowedin]

I haven't looked into tidal power recently. My impression from earlier explorations was that it was too expensive, and impractical in most locations for other reasons as well.

But it seems possible to me that such mechanisms could, like reservoirs behind dams, also act as 'virtual batteries,' which might make them a bit more attractive, perhaps?

I don't think your battery theory holds much water. When the tide is coming into a basin it is coming in right now and it is use that energy or lose it. Once it is in you could close the gates and hold it until near low tide six hours and twelve and a half minutes later. and let it all through the turbines when the head differential is greatest or you would be wasting potential energy. Wait too long and the next high tide will come in and balance out your head but if your basin was already full no more could flow in.
So you are stuck with a fixed schedule that is predictably repeated every twelve hours and twenty-five minutes but any storage you attempt will directly diminish efficiency.

[dohboi]

Good points, vt. So at best only very marginal use as 'virtual batteries.' But every new source with its own time frame makes it that much less likely that you will have long times with no power at all, and reduces the likelihood that you would need huge actual batteries for such times.

[vtsnowedin]

Good points, vt. So at best only very marginal use as 'virtual batteries.' But every new source with its own time frame makes it that much less likely that you will have long times with no power at all, and reduces the likelihood that you would need huge actual batteries for such times.

Imagine if you will factories that had to take a one hour break each day at both low and high tide because there was no power available and that these break times would rotate ahead twenty five minutes every calendar day. You could not fire up even a gas plant to cover just that two hours a day so you are forced to have full base load capacity and just let tidal power reduce load and fuel usage when it is on.
It is a pretty interesting engineering problem that is much more complicated then the political and ideological discussions would have you believe.

[dohboi]

Lots and lots of activities can, in fact, be postponed, interrupted, or carefully scheduled to correspond to known or predicted times of outgoing tides, sunny times, or high winds. As we manage those, the remainder are what will need real or 'virtual' batteries. Hospitals already have multiple backup systems. Some other critical institutions will have to do the same. No big deal.

By the way, how many actual factories are there any more in the US, anyway??

[ozcad]

Imagine if you will factories that had to take a one hour break each day at both low and high tide...

I am aware of 2 different ways of managing the flow.
1. A coastal reservoir at sea level with turbines designed to operate during tidal inflow & outflow. Max power generation is phase-shifted at 90 degrees to to the peak water level. Generation gaps occur at high and low tides, as per vtsnowedin.
2. A coastal reservoir at sea level with a broad ramp facing out to sea towards the prevailing wave source. Incoming waves will act like normal surf and rise up as they travel above the ramp, and fall into the reservoir, which will remain continuously full at a level slightly above the ocean level. Outflow via a turbine would be continuous if the reservoir is adequately sized. Disadvantage: big structure. Could be reduced in size if it only had to fill in the gaps in system 1.

[dolanbaker]

Good points, vt. So at best only very marginal use as 'virtual batteries.' But every new source with its own time frame makes it that much less likely that you will have long times with no power at all, and reduces the likelihood that you would need huge actual batteries for such times.

Imagine if you will factories that had to take a one hour break each day at both low and high tide because there was no power available and that these break times would rotate ahead twenty five minutes every calendar day. You could not fire up even a gas plant to cover just that two hours a day so you are forced to have full base load capacity and just let tidal power reduce load and fuel usage when it is on.
It is a pretty interesting engineering problem that is much more complicated then the political and ideological discussions would have you believe.

Have you ever checked the tidal forecasts, you'll see that along many coastlines, the tides are a several minutes different to the next town. With a distributed tidal system and tidal lagoons you can engineer out all the "deadspots".
The largest hurdle to such systems is of course cost!

[KaiserJeep]

The generic term for what you gentlemen are discussing is "pumped storage facility", and it is more common to use it with a series of dams at various heights in mountainous terrain. Tidal power schemes as already noted have a problem with periodacy because of the ever-changing Earth-Moon orbital mechanics, it is fairly rare to have the peak tidal flow (low tide with impounded water) coincide with the peak noontime electrical load - although such times can absolutely be predicted with great accuracy, we have been calculating tides since the 14th Century.

Hydropower facilities divide into three main types - pondage, run-of-river, and pumped storage. Pondage is an artificial lake behind an earthen dam or levee lined with concrete or clay to prevent seepage, which can be anything from a small grist mill to a huge artificial lake with multiple huge turbines. Run-of-river generation tends to be used at higher altitudes, a series of dams at lower and lower altitudes extract power and moderate floods by trapping water in a series of smaller and deeper impoundments behind classic arched concrete dams.

One of the larger pumped hydro storage facilities is a few miles south of my home in the semi-arid terrain of Central California, a large artificial lake called the San Luis Reservoir. It is actually the fifth largest reservoir in California - when it's full of water, at least. The larger California reservoirs such as Shasta or Oroville are water storage and flood abatement, the San Luis Reservoir is the largest pumped hydro in California and the fourth largest in the USA.

The basic idea with pumped storage is that dual-purpose motor/generators are designed, and during off peak hours, the generator uses excess electrical power, becoming a huge electric motor which reverses the turbine rotation and pumps water uphill back into the higher reservoir from the lower one. Such facilities then become "peaking" generators for the following day. Of course, there are two additional mechanical/electrical energy conversions involved, so there are considerable losses involved - but the excess electric power is essentially free and the losses get injected into the water as heat.

As I have reminded PO.com readers several times, there is no free lunch involved - both wind turbines and hydropower are sources of direct heat from power losses during generation, and wind turbines warm the air and hydropower warms surface water.

Yes, that's right, the renewables also cause warming. TANSTAAFL, you just cannot escape Entropy.

Nor is pumped storage usable after five years of drought in California. We have 1404 dams in this state, and 287 of those are used for hydropower - and only less than 100 of those will produce useful power this year due to reduced rainfall.