Tag: renewable energy

Technology is moving us to a world where energy is cheaper, smarter, and less carbon intensive

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The graph above is a graph of electricity demand on the Spanish electricity grid taken from the demand page of the grid management company Red Electrica de España.

The data comes from April 26th this year through to Mar 3rd. The sever small graphs along the bottom are daily demand curves, going from Tuesday April 26th on the left, through to Monday May 3rd on the right. You can see that the demand curves for each day are virtually the same.

Saturday and Sunday are however, obvious due to the lower demand on those days, and if you are wondering why Monday the 3rd looks to be lower than the rest of the weekdays, it is because that Monday was a holiday in Spain.

The large graph on top is a zoomed-in look at the demand on one of those days – Friday April 29th. From that you can see that the demand starts to rise early in the morning with the peak occurring between 8-11am. Demand then falls off until late afternoon when people are cooking their evening meals, peaking around 9pm, and then falling until it starts again the following day.

The pattern varies slightly by day of the week, as well as by season, but overall while it is variable, it is also highly predictable.

Graph of predicted energy demand vs actual demand on Spanish grid on April 29th
Graph of predicted energy demand (Green) vs actual demand (yellow) on Spanish grid on April 29th this year – graph from REE

This can be problematic though when you have high penetrations of variable energy suppliers, such as wind and solar.

Here is the energy supplied to the system by wind, for example on April 29th

Energy supplied by wind on the Spanish grid on April 29th this year
Wind energy on the 29th of April on the Spanish grid

As you can see, it doesn’t map well with the demand, and this is challenging for grid management companies, especially with increasing pressure on them to decarbonise.

That can lead to circumstances where wind power ends up supplying 140% of your demand, as happened in the Netherlands last summer. Fortunately, the Netherlands has good interconnects, and so was able to sell this excess energy to its neighbouring countries. This won’t always be the case though, and will become a more common issue as the penetration of wind and solar increases globally.

 

Obviously, if you can’t manage the supply side of the grid, what about managing the demand – how achievable is that?

Interestingly, this is now becoming a real possibility. Already there are companies who aggregate the demand of large organisations with facilities for reducing demand, if required, and sell that reduced demand to utility companies. This can save the utility from having to build new generation sources to meet the increased demand at times of peak load.

Demand flexibility graph
Demand flexibility

What if this were more widespread?

Looking at the chart above, if we could shift the yellow demand line up during its overnight dip, and then reduce the yellow demand line during the morning and evening, this would make the grid more stable, and allow for the introduction of more variable generators (solar and wind) onto the system, as well as reducing the requirement for expensive ‘peaker plants’.

Sounds great Tom, how to do that?

Well price is always a great motivator. In Germany last week where there was an excess of energy on the system, so pricing went negative, meaning large customers were being paid to use it.

Negative pricing on the German energy market
Graph of negative pricing on the German electricity market

Reduced, or negative pricing is a better option than wind farm curtailment because curtailment lowers the income for the wind farms, making them a less attractive investment for renewables developers, while reduced pricing moves the demand to a more suitable time.

Now, with the advent of the Internet of Things, everything starts to be smart and connected. If our electricity devices can listen for realtime electricity signals from the grid, they can adjust their consumption accordingly.

Of course, not all loads in the home are movable  – not many people will decide to cook their evening meal at 3am just because the wind is blowing and energy is cheap.

However, many loads are eminently movable. Pool pumps, are a good example. And also many loads that have a heating or cooling component associated with them, such as an electric hot water heater. When it is well insulated it doesn’t matter when it heats the water. Similarly for fridges, freezers, ice bank air conditioning, and so on. These are straightforward and affordable forms of energy storage.

Dish washers, washing machines, clothes dryers can also be made to listen to electricity pricing, and adjust their behaviour accordingly. Often, when you put the dish washer on in the evening, you don’t care when it comes on, as long as the dishes are clean and dry when you get up the following morning.

As more of our appliances become connected and smart, this will become the norm. Obviously, for widespread adoption, this kind of behaviour has to be totally automated. If the device owner has to think about it, it won’t happen.

Smart grid appliance

And then there are the real storage options, using batteries. This can be in the form of batteries in electric vehicles using vehicle-to-grid technologies, in-home batteries such as the ones Tesla, and others sell, or reconditioned electric vehicle batteries – a market that is just starting to get going.

So, good news, technology is moving us inexorably to a world where energy is getting cheaper, smarter, and less carbon intensive.

Apple puts its environmental initiatives front and centre at its spring event

 

LisaJacksonAppleRenewableEnergyApple held it’s annual spring event yesterday in Palo Alto to make iPhone, iPad, and iOS related announcements (amongst others).

However, this year for a change the first executive invited to address the audience was Apple’s vice president of Environment, Policy and Social Initiatives, former EPA Administrator, Lisa Jackson.

Lisa was greeted by warm applause which became more enthusiastic when she announced that 93% of Apple’s facilities worldwide are now powered by renewable energy. This means Apple is now well on its way to achieving its stated aim of being fully renewably powered globally. And in 23 countries, including the United States and China, Apple is already 100% renewably powered.

In China Jackson explained, Apple has a 40MW solar farm which has a minimal impact on the local environment, and allows for the local Yak farmers to graze their animals and grow hay under the panels (seen above). This solar farm produces more electricity than Apple uses currently in all of China.

Apple’s data centres are also fully renewably powered, and it has a policy of siting new data centres only if the site has access to renewable power. This was one of the reasons behind Apple’s choosing Ireland and Denmark for its two newest data centres last year.

In fact, since hiring Jackson away from the EPA, Apple has made some extremely positive moves in reducing its footprint, and greatly increasing its transparency. This focus on transparency may go some of the way to explaining Apple’s decision last week to move a significant portion of its iCloud storage business away from notoriously opaque Amazon to Google (although, it is as likely to do with diversifying suppliers, moving to a supplier more in line with Apple’s views on data privacy, and possibly easing the transition to eventually self-hosting the data).

Jackson also talked about Apple’s investments in forestry, and how Apple are using paper sourced from sustainably farmed forests for 99% of its packaging now.

Apple is demonstrating tremendous leadership in the energy and sustainability space (as well as the privacy space, but that another story!). Kudos to them, and interestingly Amazon appears to be finally getting around to supplying some of its operations with renewable energy too – though, it still shuns any kind of auditing or reporting on its energy and emissions. Sigh, maybe someday after seeing Apple put their environmental initiatives front and centre, Amazon will also see the value of doing this.