Global Solar Power Generation

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Whilst watching SBS TV this afternoon, I twice noticed an ad for a program titled “Years Of Living Dangerously” to be broadcast on SBS TV this Sunday, and the claim that the US had less than 1 million homes with solar power grabbed my attention.

The first series of thie program was in 2014 but it appears that there has not been any substanial improvement, with data revealing that by 2019, just 2 million US homes had solar power, around the same number as Australia, despite the US having around 12 times our population.

And according to this Wikipedia webpage, Australia is the world leader in solar power generation per person.

As for why such a massive discrepancy exists, one has to wonder whether in the case of US consumers, power prices are too cheap, solar power systems are unaffordable, or vested interests have sabotaged the uptake of solar.

At least Australia is doing something right.


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No need to comment?
Paybacks in the USA vary from 6 years to more than 15:

System prices of over US$20,000 typically include a battery.

Average annual household electricity consumption is quoted at 900kWh per month 10,800kWh pa. Australia 5,000-7,000kWh.

The average cost of electricity depends.
Some states/providers use net tariffs for solar feed in, which sounds really good, but they may also come with TOU tariffs.

For roof top residential solar PV, there are at least 50 different versions. Every state is different? Nothing new in that. The 50 excludes Washington DC and the five territories with permanent residents.

The USA does have a high rate of increase in solar PV, just not rooftop. Although California has high ambitions. an interesting point is the state believes it can generate up to 73% of total electricity needs from rooftop solar, and in doing so avoiding environmental loss of desert lands to solar farms.

And don’t mention Australia’s slow EV up take.
In the first half of 2020 sales of pure BEVs in the USA totalled 87,398.


I believe power is cheaper in the USA, less incentive to generate your own. I think Australia is headed for a big problem. It costs more to transport electricity than to generate it. The poles and wires are designed for a maximum demand, which with solar generation comes around less frequently. But it is still there because solar is intermittent. So as average demand falls due to uptake of solar, what comes from the grid has to become more expensive to cover the maintenance of the poles and wires. That pushes more people to solar so the problem gets worse. I haven’t seen a sensible solution to this.

No quite right and only true if there is storage.

The peak generation for solar is about 5 hours timeshift to the peak demand on the network. In the past few decades, peak demand have shifted to around 5-6pm, where as most north facing solar (which is the predominant facing direction) peaks around noon.

If one captures some of the peak daily solar generation in storage and releases that stored 5 hours later, then solar could have a impact on peak demand, and network design.

The poles and wires capacity is only slightly impacted by solar due to this time shift. Even with more residential solar generation added without storage (as storage is unreliable and uneconomic), the existing capacity with redundancy would still be needed to protect the network in periods of peak demand.

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I don’t think it changes my point, which was - poles and wires designed for peak demand, but paid for by average demand. If average demand falls because of local generation, but peak demand remains the same, then the cost of poles and wires has to be covered by raising the price of the lower average demand. Price goes up, people move to solar, average demand goes down further, vicious circle.

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I agree with you @WatchThisSpace. I don’t know where you are but I am in Melbourne. The whole electricity system was built and run by the SEC. Then it was sold off in the 90s. BUT, the “poles and wires” part, both the high voltage long distance, and medium voltage local distribution, remained monopolies, and could and did charge whatever they wanted and could get away with.

An easy conclusion. There are proposals to invest even more in the poles and wires, which also includes all the transformers, switching, protection and regulating infrastructure. It’s driven by the increased PV generation feeding into the grid.

How much needs to be done depends on the extent of local storage implemented and micro grid alternatives. The more centralised the redesign of the national grid and distribution the more it is likely to cost. The worst case outcome is rooftop PV owners having to pay to use the grid for all export. In reality that export is unlikely to make it much further than the end of the street, or suburb. The consumer, or those reliant on the grid will likely pay for either outcome.

The NEG can function as a centralised generation and storage system, or it can function as a pathway for a substantial decentralised system to trade surplus energy or import shortfalls. The latter might be with other decentralised users, or with one of a number of contestable sources providing large scale long term storage and supply for top up. Peak demand flows are replaced by less intense balancing flows of energy across the network.

A vision:

And a recent update on what might be contemplated:

One solution increasing the use of residential or end of street battery storage to charge in the daytime and reduce peak demand is available. For home owners the economics are held back by flat feed in tariffs or TOU tariffs that undervalue the savings in reduced high cost peak demand? Controlled discharge Residential battery storage also has the potential to reduce peak middle of day solar PV feed in. This could defer the need for action upgrading the distribution side of the poles and wires? Residential battery storage is undervalued. It threatens the business models of all the large electricity enterprises. They can make very large profits out of the spot pricing around meeting supply during peak demand periods.

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No this isn’t quite correct either.

While the network has been designed for reliability during maximum loads on the network (peak demand), it is paid through network fees attached to each unit of consumption (kW).

The transmission and distribution networks charges operate in a similar way to a toll road. The amount of money paid per car at each toll booth is the same and doesn’t change based on the level of traffic. If there are 100 cars through the toll booth each day, then the revenue would be 100 x toll. If there were 5000 cars per day, the toll for each car at the toll booth remains the same and the revenue would be 5000 x toll.

The network charges are attached to the unit of electricity used (kilowatt), just like attached to a car using a toll road. So, irrespective of the amount of energy used or flowing on the network, the unit rate of the network charge remains the same. Therefore, in periods of peak demand, the amount of network charges would be at a maximum and if the demand was 50% of peak demand, the total network charge paid by consumers for be 50% of that which would have occurred at the time of peak demand.

Therefore, the payback of the assets has little to do with the demand on the network but the total flow on the network.

The network is however designed to be reliable at times of peak demand. As we live in a developed, industrialised country, the community/electricity consumer has an expectation that electricity will be available at all times. This is particularly the case when electricity is most needed on hot days for cooling/refrigeration and cold days for heating. These cold and hot days also correspond to days of peak demand.

The effect is the less total flow on the network (between major generators and consumers) means that while the depreciation, operating and maintenance costs on the network remain the same, these costs are spread over a smaller total flow. Over time the network charges increase to ensure the same amount of revenue is generated. One an network asset is built, the depreciation, operating and maintenance costs remains almost the same.

As the network is designed for peak demand, the reduction in flow during the middle of the day hours has little impact on the design of the network…as the peak demand occurs at a different time as outlined in the previous post.

Those with solar installed has in effect increased the network charges for everyone on the network including those with out solar, which in many cases are those who can least afford higher electricity prices or the upfront cost to install solar.

If there was sufficient storage in the network, peak demand could be reduced reducing the network costs associated with delivering a reliable supply at peak demand. In such case, over the longer term the depreciation, operating and maintenance costs of the network would reduce and be passed onto consumers. Unfortunately since domestic storage is unreliable and uneconomic, it is unlikely to be a contribution in the short to medium term.

Having worked in the network industry, if the State Government solar programs had been run differently, we would face the challenges which exist at the moment.

I’d not discourage others from making the decision to install a home battery. There is sufficient reliable information available on the benefits and risks. Understanding existing industry business models and economics are not in their favour is the most significant IMO.

There is always a cost to change. Consumers make many decisions to spend based on very non economic reasons. Holiday travel, and Netflix subscriptions are common examples, as is the ability of some to choose prime Wagu beef and Coffin Bay Oysters over chuck steak and seafood extender sticks.

There is sufficient experience of others with battery systems to suggest reliability is acceptable to many. Tesla Powerwall users in general.

The economics are more in the hands of the vested interests than the consumer. A longer discussion that might challenge the integrity of the industry. If indeed it has any? It exists mostly to take profit, and add shareholder value through growth. Handing any portion over to consumers is against good business principles.

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When our solar and battery system reaches its 2 year anniversary early next year, I will post full details regarding the performence over that period for the benefit of anyone interesred.

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I’m sorry but am I missing something?

Isn’t that the same as

And reading the vision, it says nothing about cost. They know they have a problem, they are proposing various ways of tackling it, they summarise the benefits of each approach (non of which seem that optimistic). I still think none of these will lower the cost of grid electricity.

But one which is often proved true.

You say twice the economics are not on the consumers’ side. You also say that they should not be discouraged and that reliability is acceptable to many. What are we to conclude from that, that consumers are making decisions based on non-economic criteria and ought to be left alone to waste their money if they so desire?

Value for money features as a criterion for consumer spending nearly always but not this one. Perhaps it is in the meaning of ‘value’. Like a Lamborghini is value to some as a status symbol and chick magnet.

No, average demand is the average demand on the network. Network charges aren’t based on average demand but forecast total energy transmitted across the network (amount of energy that flows on the network from the main generators to the consumers).

The way network pricing is calculated is the network operators make an application to the regulator based on their planned forward costs and the regulator reviews these, makes adjustment and then calculates the network charges based on the forecast total energy transmitted across the network. This process is call a reset and occurs every 5 years.

In the past decade and due to changing demand profiles, the AER has been placing downward pressure on network costs submitted to the AER as part of a reset. Downward pressure has been achieved by discounting the costs.

That is correct, and currently the information points to domestic battery systems being unreliable (high failure rates) and uneconomic. These possibly the two main decision points often used when making a decision to install a battery.

One may chose to install a battery for other reasons , and hopefully knowingly and accept current known risks.

Consumers often buy products which are known not to be reliable and/nor economically practical, but chose to do so for other reasons.

WA is currently facing the very issue at the heart of increased solar PV.

It’s a remarkable proposal:

Key points:
The trial will include 400 customers of State-owned provider Synergy
Customers will pay 8 cents per kilowatt hour between 9:00am and 3:00pm
That increases to 55 cents per kilowatt hour between 3:00pm and 9:00pm

Are the savings for a large household sufficient to add a battery?
Or will consumers adopt a different way of living.

One WA generating business is under pressure without any change in the status quo.

If the trial became the norm, it also increases the benefit of investments in distributed storage, typically more cost efficient than individual household systems.

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If they do what happens if the experiment is terminated and the pricing structure reverts to a more normal one?

average demand = (total energy transmitted)/(period over which that energy is transmitted)

We are talking about the same thing, just using a different way of measuring it.

I don’t see a great future for the home battery, too many small units with limited lifespans using relatively expensive elements. There is a medium size solution that has great promise, the liquid metal battery - see The cells run at 500°C, don’t degrade with use so have an as yet indeterminate lifetime. If there were one of these for a few suburban blocks, most of the power stays local and if they need extra charging this can be done while demand is low. I think Ambri are the only company with a commercial product but there are other cheaper metals that can be used, but usually require higher temperatures. Power companies are not going to jump at this while they can charge whatever they like. Should be a major government initiative to research this.

Average demand is what consumers use (inc losses) on the network. It is a actual measurement.

Forecast total energy transmitted across the network is what is estimated to flow over a future period. The information comes from models network planners use and has a range of inputs including historical demand, anticipated changes in generation, anticipated changes in consumption, weather etc. It isn’t a measurement but a modelled result. The modelling provides information on where flows will occur and the infrastructure costs associated with these flows. Depending on the part of networks used and nature of the demand, for the same estimated future average demands there can be two different network costs. This is why flow is used instead of ‘average demand’.

Modelled results are used as network costs are based on future network flows, not current or past demand. I tried to indicating this in the last post.

As there are interconnectors between eastern states, modelling flows is important as demand in one state can impacts on flows and networks within and between states.

I agree.

I am surprised that one of the battery (any form of energy storage) companies hasn’t allowed investment/purchase shares into a battery farm where one buys battery capacity and can use stored electricity (say when pool prices are low) to offers set one’s energy use (when pool prices are relatively high). This makes more sense than batteries scattered throughout the suburbs which poses a number of network, safety etc challenges. Having them all in one place managed well makes sense.

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Consider to whose financial benefit this might work best?

The current supply arrangements are far from zero profit, nor are they truely a free market. Unless for a consumer the choice to buy from the grid or not to connect is considered a free market. The market has been regulated, alternately managed to assure most involved a steady profit stream (governments included).

The CEC has pointed out the scope of the significant industry reforms required, to maximise the benefits of increased supply of low carbon energy. March 2017. There has been plenty of time to be prepared. Not much has changed since?

So this discussion seems to centre around home Solar being the only clean energy source. Wind can operate 24/7 most days, perhaps Hydro/Geothermal etc. Producing Hydrogen via Solar as a Fuel source and backup power. And Nitrogen Batteries as well as the Lithium Iron batteries mean their are plenty of choices. Many countries like Denmark/Norway even the UK use far more renewable energy (Wind being the Predominate one) 60% + and their peak grid times cope because they ave new flexible systems and Governments not tied to Coal like we are. And the onset of EV’s means even more grid sharing. As Nissan’s Chademo and the New Honda E CCS both can feed back to the grid. And they have a home pack in Japan that does that. So EV can charge on solar during the day and give back 10kwh or less to the grid if parked at home during peak hour. Their are many solutions NOW and even more coming soon.

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This is not correct.

Bioenergy (burning waste and green waste), solar and wind and solar only make up 20-35% of the UK total electricity production. Nuclear is around 10-15%, gas around 25-35% and coal less than 5%. The UK is heavily reliant on imported energy (~5% interconnector), gas and nuclear to maintain a reliable dispatchable electricity supply.

There has been misinformation circulating on social media about UK electricity mix which may have taken to be true, without confirming from the UK government agency responsible for managing it’s supply.

Long term change in electricity mix within the UK can be found here:

This is also incorrect. Norway relies heavily on hydrogenerations which accounts for about 96% of its electricity generation.

Demark is heavily reliant on wind (60% of its electricity), but like many other European countries relies on interconnector, nuclear and non-renewable energy for dispatchable supply.