Earth’s inside for better air 2

In our 2012 article Earth’s inside for better air, we explained that New Zealand is a country where geothermal energy is widely developed. We mentioned Wairakei power plant, the second commercial geothermal plant opened in the world. This was in 1956. New Zealand was world leading! Well, being in New Zealand again, we decided to go to the plant…

HAPPY TO BE THERE, READY TO DO MORE

“We are committed to protect the quality and quantity of water to New Zealanders,” Rosanne says. We had the chance to meet Rosanne Jollands, Community Relations Manager and Genelle Slack, Senior Environmental Advisor, at the power plant. The installation has a capacity of 156MW. It is operated by the company Contact, employing 120 people on site.

Genelle on the left and Rosanne on the right.

Geothermal plants exploit natural hot underground waters to generate electricity. They release very few quantities of greenhouse gases compared to coal or gas power plant. Fortunately New Zealand has decided to use its strong geothermal potential. Genelle says: “Currently 82% of the energy comes from renewable sources. It is a very good figure. The objective is to reach 90% by 2020.” New Zealand runs a national carbon emission trade market where “the price of one ton of CO2 is currently around 18 NZD. Such a trade market aims to reduce the country’s emissions year after year by progressively increasing the price of an emitted ton.”

 This small chart describes how a geothermal plant works. ©Mercury

We used a nice plug-in hybrid
car to visit the plant!

Genelle adds: “Still our power plant generates greenhouse gases. This is why we invest in projects to reduce further the carbon footprint, and then pay less within the emission trade market. One ongoing project deals with two gases produced during the operations, carbon dioxide and methane. Today they are released to the atmosphere. We want to inject them into to the cold water which is going back to the ground. Such an additional process is viable only thanks to the carbon price.” The experts working on the international negotiations on climate change agree that a major next step is the definition of a carbon price, at the international level.

GENERATING ELECTRICITY, BUT NOT ONLY

“Earlier this year the World Geothermal Conference was held in Melbourne,” Rosanne explains. “Right after the Conference, Contact received many visitors here at Wairakei plant. All these visitors wanted to know more about how we operate here.”

A prawn farm, right outside the power plant.

Rosanne adds: “We do not only produce electricity here, the extracted hot water also goes out to few places nearby. One of them is a prawn farm; another one is hot pools!” Direct use of geothermal waters can supply heat for industrial processes. For instance, in Kawerau, northern New Zealand, the geothermal hot water is directly used by a paper mill. In Iceland, Hellisheidi plant is one of the several plants of the island; it provides 300MW of power but also hot water to the Capital city Reykjavik. Likewise, in numerous districts around the world, the extracted water is used to heat buildings. Earlier this year, we could visit the ecodistrict Fort d’Issy, in France, where 1500 modern apartments are heated by a geothermal installation. Philippines and Italy are other world leaders in geothermal energy. Let’s follow them!

Hellisheidi in Iceland, and the ecodistrict Fort d’Issy (©On Power/ ©Ville d'Issy-les-Moulineaux).

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In 2013 New Zealand generated 7,6 tons of CO2 per capita, way lower than its neighbor Australia, who produced 16.3 tons but a little bit more than France with 5,1 tons which is the same figure as the world average. The country who emitted the most in 2013 was Qatar with 40.5 tons per capita. More from the World Bank database here.

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Store electricity, and everything can switch

Electricity is a beautiful thing. It changed our world during the 20th century, like motorized vehicles also did or like internet is transforming our society. Yet there is one standard which has to evolve about electricity: the storage of it. Today we do not store large quantities of electricity, or only occasionally. Humanity needs to find ways to store large amounts of electricity because in the future more electricity will have to come from solar and wind energy…

THE INTERMITTENCE AFFAIR

An example of pumped hydro storage
on El Hierro island, Spain -
 This is the superior reservoir of
the installation (©AFP).

In some places around the world, there are days during the year when 100% of the electricity comes from renewables. Without electricity storage. But these places are Portugal or Denmark: a few million inhabitants in a sunny and/or windy coastal region. And depending on the weather, this 100% is not reached every day.

Solar and wind are intermittent. They do not necessarily produce the electricity at the moment we need it. Actually solar produces more electricity in the middle of the day and we need it more at the beginning and end of the day. The non-consumed electricity is just lost, except if you store it! In the previous article, we presented an exciting new class of solar cells. Progress in intermittent electricity generation will have to go with progress in storage.

Today the most common technology for storage is pumped hydro storage: pumping water up to a reservoir, and releasing it when electricity is required. The released water goes through a turbine which generates the current, like in a dam. We find such installations in Switzerland or France for instance. But this option has large footprints; it cannot be implemented everywhere. It looks like what we need is efficient batteries…

AND TESLA CAME IN THE GAME

Innovation is giving us new batteries. These batteries will store more electricity and will cost less, together with a very small environmental footprint. They will change the game! Actually the change has started. Big batteries can be installed at your house or at your office building. They store electricity coming from solar panels, for instance, and provide it when you need it. For several years already this home battery has been available for purchase, however the real change has started recently. The Californian company Tesla is helping…

In New Zealand, Vector has installed nearly 200 Tesla home batteries during the last 5 months. Vector is the New Zealand largest distributor of electricity and gas. Several years ago the company decided to lead the switch to the green energy technologies. Since mid 2016 they have started to install the Tesla battery solutions, as the only distributor in New Zealand. We had the opportunity to meet Andrew Fraser who is the New Projects Manager at Vector. Andrew could tell us more about their part in this story.

We met Andrew at Vector's head office, in Auckland.

There are two main Tesla products: the Powerwalls and the Powerpacks. The Powerwalls are designed for home; the Powerpacks are designed for businesses or institutions as they offer larger storage capacity. The home Powerwall is dimensioned to meet the demand of a family of four without problem, around 5kWh per day. Most of the time, Vector has provided both the home battery together with solar panels. This is the typical combination.  

Andrew explains that recently Rongamai School in South Auckland had a Powerpack installed, together with solar panels, for a four classroom block. The electricity consumption is monitored and the figures are thrilling: 95% of the consumed electricity comes from the solar panels! It does the job.
 

Vector CEO, Simon Mackenzie, Project Manager Paul Cannin and Minister of Energy and Resources, Hon Simon Bridges, at Auckland Glen Innes power substation (©Vector). On the 20th of October, the Minister opened the first grid-scale battery system installation of Asia Pacific. The substation homes several Powerpacks which will allow the suburb to better face the consumption peaks. The Powerpack is a cabinet containing 16 batteries like the one found in a Powerwall. In a Los Angeles western suburb, a similar project has started recently: the Long Beach facility will host a massive battery storage system.

R&D PEOPLE ARE WORKING HARD ON IT

The year 2016 was a ramp-up for Vector. The distributor sells the "Powerwall and solar panels" package at around 20000NZD (around 13500€), the Powerwall costing around 10000NZD alone. The prices will decrease in the near future together with the growing market, and with innovation. Innovation will allow Tesla and other designers to change the chemistry of the batteries. Also their environmental cost is high today, including the Tesla ones. But it will go down. The Advanced Research Projects Agency-Energy (ARPA-E), in the U.S., is one of the numerous places developing encouraging solutions. One promising battery uses abundant sources such as oil waste or rhubarb. It is much cheaper and less toxic than current batteries.

Solar and wind farms producing and storing electricity will allow using less and less coal and gas power plants. Things will go even further since each building and each house could generate and store electricity. This is just the beginning...

 The Sydney Tesla store exhibits the Powerwall.

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In a 2012 article we talked about smart grids in Perth, Australia. Decentralized generation and storage of electricity will have to go with advanced electricity distribution grids. This changes the business model of electricity suppliers; they need to adapt to this switch.

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