Power shares

[xafalcon]

with solar you have simple timers fitted on the fuses for hot water tanks/sewerage tanks /bores etc-run these between 10am and 4 pm.
Maybe small scale pumped hydro might be possible for one of my 2 properties It has a 30 metre deep bore with its own tank.

A better solution for resistive loads like a hot water cylinder, is to use a solar power diverter. This uses a CT clamp on the main power feed to the house, and diverts power that would otherwise be exported, into heating the hot water. It only diverts the excess power, avoiding importing power when the sun goes behind a cloud. Also works well with my battery system

[fish]

Thank you.
None of the solar installation companies mentioned this-just charged me a lot for replacing load fuses with mini timers .

Sounds like a cheap non-invasive set-up to reduce the power bill with solar

Seriously thinking that mini-pumped hydro using an existing bore pump operating as directed by ct clamp to store power in a 30000 l. Water tank and then a mini-turbine to generate power at night could be a very effective battery .

[cyclist]

Thank you.
Seriously thinking that mini-pumped hydro using an existing bore pump operating as directed by ct clamp to store power in a 30000 l. Water tank and then a mini-turbine to generate power at night could be a very effective battery .

Sadly the numbers don't really stack up, even if you have a very high hill to pump it to. For example 4 l/s flow over a 10m head will give you around 167W output (using this calculator). That 4 l/s flow rate is going to drain your tank in a little over 2 hours (4 l/s = 4*60*60 = 14400 l/hr). You've generated a massive 0.35 kWh over that period. It will be better the more head you have available, but still pretty unviable.

[fish]

Thanks cyclist for the calculation.
clearly not viable small scale.
however if there was an area above and close to lake taupo that could store water this could act as a low cost battery without the complexities risks and costs of a think big project as lake onslow.
I feel widespread adoption of solar and wind, supplemented with underground gas storage and retention of Huntly burning clean gas in dry years is the sensible future .

[Shareguy]

Thought this article from Business desk sums Onslow up well.

Here are 10 big problems with the Onslow proposal:

1. It won’t be ready in time. The Infrastructure Commission’s report on harnessing NZ’s renewable energy potential, published this week, is blunt. “Our calculation is that [Onslow] will not be available until 2037 at the earliest.” The government is targeting 100% renewable electricity by 2030, so Onslow will be at least seven years too late to contribute to that outcome. In the meantime, there are 15 years of economic and electricity demand growth that needs to be met somewhere.
2. No one really knows how much it will cost. Estimates from backers suggest $4b. Critics say it could be $8b-plus and has all the hallmarks of the Clyde Dam project’s cost blowouts.
3. No one really knows if the project can be done. This is a subset of the cost question. A tunnel of more than 20 kilometres through the schisty, unstable rock of central Otago is inevitably a gamble. The $100m feasibility study under way is intended to help answer this question. But the potential for expensive discoveries long after the project has been given the green light is substantial. It could also take far longer than estimated to complete.
4. There are better, lower-cost alternatives. These will get us to the same outcome – and sooner. NZ has wind, geothermal, solar and potentially biomass and carbon capture use and storage (CCUS) options that can produce electricity at competitive prices today and within the next decade.
5. New renewable investment is discouraged. It's much less likely to occur if the spectre of a massive market intervention sits on the horizon, 15 years out. It's far more likely that fewer renewable wind and other power plants will be built in the interim, with coal and gas-fired power stations taking up the slack until Onslow arrives. In other words, Onslow would likely mean higher carbon emissions than could be achieved by other means.
6. Onslow is an old technology solution. New, post-carbon technologies are rapidly emerging. One example: green hydrogen production. Meridian and Contact say they're serious about this and that there's enough untapped wind energy in Southland to build a green hydrogen plant that would use as much power as the Tiwai Point aluminium smelter. Note: the smelter could continue running too – as long as it pays a much fairer price than it does now for 85% to 98% renewable electricity to make “green” aluminium. But a big part of the green hydrogen concept is being able to turn the production process up and down at will. During dry winters, a green hydrogen plant could throttle right back and sell its electricity into the grid instead. That would give it precisely the same effect as Onslow, but without the taxpayer having to build Onslow. If Onslow is built, the business case for green hydrogen and a whole new post-carbon industry evaporates.
7. If it's a battery, there will be better ones. Onslow’s main justification is that it acts as a battery, but the Infrastructure Commission suggests there will be better batteries available by 2037. “By that time, inter-seasonal battery storage could be feasible and cheaper, and a more flexible option. Other approaches may also offer better value, such as biomass 'peakers' that only operate for increased demand from electricity users. In other words, we might still burn small amounts of gas to make electricity when there are shortages, but that gas could be net-zero-carbon biofuels relatively soon. If we wanted to store up biofuels, they could be stored the same way as gas is today – underground, in naturally occurring reservoirs.
8. Onslow is not commercially viable. And it has never been seen as a commercially viable project. It's promoted as an all-eggs-in-one-basket, public-good investment that will always use more electricity pumping water uphill into its reservoir than will be produced from that reservoir. The only reason this can make sense is that the water would be pumped uphill when power is cheap and released when it’s expensive. That's exactly how the green hydrogen proposal works, too. Make ammonia or hydrogen when electricity is cheap, which we could use to power cars, trucks, and industrial processes that now use fossil fuels. When it’s more valuable to use energy to make electricity than hydrogen, turn down the hydrogen plant.
9. Private investors. They would back green hydrogen – not the taxpayer – and its development would support massive extra investment in new renewable electricity. Onslow would do neither. A study for Meridian and Contact by Concept, an energy consulting firm, concluded last year that “the highest cost option [for energy security of supply] is building a large South Island pumped storage scheme, due to having to recover the costs associated with building such a scheme”.
10. Look at the other options. Even massively overbuilding wind or solar electricity generation to cope with dry winters would be likely cheaper than building the Lake Onslow project.

...And then, of course, there’s the question of resource consent. But that, in my view, is the least of the impediments to an idea so bold as to be obscuring its manifest flaws.

[LaserEyeKiwi]

Thought this article from Business desk sums Onslow up well.

Here are 10 big problems with the Onslow proposal:

1. It won’t be ready in time. The Infrastructure Commission’s report on harnessing NZ’s renewable energy potential, published this week, is blunt. “Our calculation is that [Onslow] will not be available until 2037 at the earliest.” The government is targeting 100% renewable electricity by 2030, so Onslow will be at least seven years too late to contribute to that outcome. In the meantime, there are 15 years of economic and electricity demand growth that needs to be met somewhere.
2. No one really knows how much it will cost. Estimates from backers suggest $4b. Critics say it could be $8b-plus and has all the hallmarks of the Clyde Dam project’s cost blowouts.
3. No one really knows if the project can be done. This is a subset of the cost question. A tunnel of more than 20 kilometres through the schisty, unstable rock of central Otago is inevitably a gamble. The $100m feasibility study under way is intended to help answer this question. But the potential for expensive discoveries long after the project has been given the green light is substantial. It could also take far longer than estimated to complete.
4. There are better, lower-cost alternatives. These will get us to the same outcome – and sooner. NZ has wind, geothermal, solar and potentially biomass and carbon capture use and storage (CCUS) options that can produce electricity at competitive prices today and within the next decade.
5. New renewable investment is discouraged. It's much less likely to occur if the spectre of a massive market intervention sits on the horizon, 15 years out. It's far more likely that fewer renewable wind and other power plants will be built in the interim, with coal and gas-fired power stations taking up the slack until Onslow arrives. In other words, Onslow would likely mean higher carbon emissions than could be achieved by other means.
6. Onslow is an old technology solution. New, post-carbon technologies are rapidly emerging. One example: green hydrogen production. Meridian and Contact say they're serious about this and that there's enough untapped wind energy in Southland to build a green hydrogen plant that would use as much power as the Tiwai Point aluminium smelter. Note: the smelter could continue running too – as long as it pays a much fairer price than it does now for 85% to 98% renewable electricity to make “green” aluminium. But a big part of the green hydrogen concept is being able to turn the production process up and down at will. During dry winters, a green hydrogen plant could throttle right back and sell its electricity into the grid instead. That would give it precisely the same effect as Onslow, but without the taxpayer having to build Onslow. If Onslow is built, the business case for green hydrogen and a whole new post-carbon industry evaporates.
7. If it's a battery, there will be better ones. Onslow’s main justification is that it acts as a battery, but the Infrastructure Commission suggests there will be better batteries available by 2037. “By that time, inter-seasonal battery storage could be feasible and cheaper, and a more flexible option. Other approaches may also offer better value, such as biomass 'peakers' that only operate for increased demand from electricity users. In other words, we might still burn small amounts of gas to make electricity when there are shortages, but that gas could be net-zero-carbon biofuels relatively soon. If we wanted to store up biofuels, they could be stored the same way as gas is today – underground, in naturally occurring reservoirs.
8. Onslow is not commercially viable. And it has never been seen as a commercially viable project. It's promoted as an all-eggs-in-one-basket, public-good investment that will always use more electricity pumping water uphill into its reservoir than will be produced from that reservoir. The only reason this can make sense is that the water would be pumped uphill when power is cheap and released when it’s expensive. That's exactly how the green hydrogen proposal works, too. Make ammonia or hydrogen when electricity is cheap, which we could use to power cars, trucks, and industrial processes that now use fossil fuels. When it’s more valuable to use energy to make electricity than hydrogen, turn down the hydrogen plant.
9. Private investors. They would back green hydrogen – not the taxpayer – and its development would support massive extra investment in new renewable electricity. Onslow would do neither. A study for Meridian and Contact by Concept, an energy consulting firm, concluded last year that “the highest cost option [for energy security of supply] is building a large South Island pumped storage scheme, due to having to recover the costs associated with building such a scheme”.
10. Look at the other options. Even massively overbuilding wind or solar electricity generation to cope with dry winters would be likely cheaper than building the Lake Onslow project.

...And then, of course, there’s the question of resource consent. But that, in my view, is the least of the impediments to an idea so bold as to be obscuring its manifest flaws.

I actually think Onslow will go ahead, and it will be part of a “Why not both?” Long term strategy.

Onslow will be viewed as a strategic national asset, not just for reserve power generation, but also (and this is often overlooked) for its value as a very large freshwater storage facility. Ideally it would also be topped with a very large floating solar farm (as they do on lakes in China).

[Monarch]

What is the benefit of using it to store fresh water given its location? One or two small cities and some farms get a boost to water security?

[xafalcon]

Thought this article from Business desk sums Onslow up well.

Here are 10 big problems with the Onslow proposal:

1. It won’t be ready in time. The Infrastructure Commission’s report on harnessing NZ’s renewable energy potential, published this week, is blunt. “Our calculation is that [Onslow] will not be available until 2037 at the earliest.” The government is targeting 100% renewable electricity by 2030, so Onslow will be at least seven years too late to contribute to that outcome. In the meantime, there are 15 years of economic and electricity demand growth that needs to be met somewhere.
2. No one really knows how much it will cost. Estimates from backers suggest $4b. Critics say it could be $8b-plus and has all the hallmarks of the Clyde Dam project’s cost blowouts.
3. No one really knows if the project can be done. This is a subset of the cost question. A tunnel of more than 20 kilometres through the schisty, unstable rock of central Otago is inevitably a gamble. The $100m feasibility study under way is intended to help answer this question. But the potential for expensive discoveries long after the project has been given the green light is substantial. It could also take far longer than estimated to complete.
4. There are better, lower-cost alternatives. These will get us to the same outcome – and sooner. NZ has wind, geothermal, solar and potentially biomass and carbon capture use and storage (CCUS) options that can produce electricity at competitive prices today and within the next decade.
5. New renewable investment is discouraged. It's much less likely to occur if the spectre of a massive market intervention sits on the horizon, 15 years out. It's far more likely that fewer renewable wind and other power plants will be built in the interim, with coal and gas-fired power stations taking up the slack until Onslow arrives. In other words, Onslow would likely mean higher carbon emissions than could be achieved by other means.
6. Onslow is an old technology solution. New, post-carbon technologies are rapidly emerging. One example: green hydrogen production. Meridian and Contact say they're serious about this and that there's enough untapped wind energy in Southland to build a green hydrogen plant that would use as much power as the Tiwai Point aluminium smelter. Note: the smelter could continue running too – as long as it pays a much fairer price than it does now for 85% to 98% renewable electricity to make “green” aluminium. But a big part of the green hydrogen concept is being able to turn the production process up and down at will. During dry winters, a green hydrogen plant could throttle right back and sell its electricity into the grid instead. That would give it precisely the same effect as Onslow, but without the taxpayer having to build Onslow. If Onslow is built, the business case for green hydrogen and a whole new post-carbon industry evaporates.
7. If it's a battery, there will be better ones. Onslow’s main justification is that it acts as a battery, but the Infrastructure Commission suggests there will be better batteries available by 2037. “By that time, inter-seasonal battery storage could be feasible and cheaper, and a more flexible option. Other approaches may also offer better value, such as biomass 'peakers' that only operate for increased demand from electricity users. In other words, we might still burn small amounts of gas to make electricity when there are shortages, but that gas could be net-zero-carbon biofuels relatively soon. If we wanted to store up biofuels, they could be stored the same way as gas is today – underground, in naturally occurring reservoirs.
8. Onslow is not commercially viable. And it has never been seen as a commercially viable project. It's promoted as an all-eggs-in-one-basket, public-good investment that will always use more electricity pumping water uphill into its reservoir than will be produced from that reservoir. The only reason this can make sense is that the water would be pumped uphill when power is cheap and released when it’s expensive. That's exactly how the green hydrogen proposal works, too. Make ammonia or hydrogen when electricity is cheap, which we could use to power cars, trucks, and industrial processes that now use fossil fuels. When it’s more valuable to use energy to make electricity than hydrogen, turn down the hydrogen plant.
9. Private investors. They would back green hydrogen – not the taxpayer – and its development would support massive extra investment in new renewable electricity. Onslow would do neither. A study for Meridian and Contact by Concept, an energy consulting firm, concluded last year that “the highest cost option [for energy security of supply] is building a large South Island pumped storage scheme, due to having to recover the costs associated with building such a scheme”.
10. Look at the other options. Even massively overbuilding wind or solar electricity generation to cope with dry winters would be likely cheaper than building the Lake Onslow project.

...And then, of course, there’s the question of resource consent. But that, in my view, is the least of the impediments to an idea so bold as to be obscuring its manifest flaws.

The report is written to discourage Lake Onslow going ahead

1 = rubbish
2 = the same for any project, even short term projects like building a house
3 = under evaluation, and may become overland
4 = more of the same won't work in dry years. Wind is unpredictable, solar doesn't work at night or in the winter, geothermal is close to maximised already and isn't carbon free
5 = rubbish
6 = old tech is proven tech. This is a benefit in this instance. Other storage media is not suitable for long term storage. Hydrogen will NEVER trump direct electricity generation, production losses are astronomical
7 = there probably will be better batteries, but not for long term storage. Batteries are fine for peaker demand, not for longer term storage (weeks/months)
8 = Onslow will be a government funded project, so commercial viability is irrelevant. It will have the public-good function of lowering power prices by arbitrage. This is the real "commercial viability" that the current generators are so worried about
9 = irrelevant, see pt8 above
10 = appears to be the same as pt4?? Clearly the authors wanted 10 points, but by duplicating, they have come up short.

[Monarch]

I think Onslow would make a lot more sense if NZ had a power linkage to Australia similar to the Australia-Asia power link that is in development now. They have heaps of solar energy generation and huge future potential solar capacity expansion, but lack energy storage (power prices were going negative during the day in solar heavy states). Onslows cost per kwh of storage is compelling but I do wonder if we need to have so much storage. Onslows purpose is also partially political (to combat climate change) and helping AUS with their storage problem would further this goal given something like 0.6% of global emissions are from the AUS electricity network.

[xafalcon]

I think Onslow would make a lot more sense if NZ had a power linkage to Australia similar to the Australia-Asia power link that is in development now. They have heaps of solar energy generation and huge future potential solar capacity expansion, but lack energy storage (power prices were going negative during the day in solar heavy states). Onslows cost per kwh of storage is compelling but I do wonder if we need to have so much storage. Onslows purpose is also partially political (to combat climate change) and helping AUS with their storage problem would further this goal given something like 0.6% of global emissions are from the AUS electricity network.

Onslow only seems big by today's electricity usage. In 10 years time there will be much more electrification of process heat and transport. Plus, it's always good to build it big sooner rather than later, as construction cost never declines over time