Tag Archives: hybrid renewables

100% Australian Renewable

Posted on by
1

What does 100% renewable electricity for the whole of Australia look like?

WHO: The Australian Energy Market Operator, commissioned by the Australian Federal Government

WHAT: Modelling for what a 100% renewable national electricity grid for Australia would look like.

WHEN: July 2013

WHERE: Online at the Department of Climate Change website

TITLE: 100 PER CENT RENEWABLES STUDY – MODELLING OUTCOMES (open access)

The Australian Department of Climate Change (yes, they have one!) commissioned the Australian Energy Market Operator in conjunction with CSIRO and ROAM Consulting to model what a national energy market would look like in 2030 and 2050 with 100% renewable electricity. Oh, and when they say ‘national’ they mean the more densely populated East Coast of the country (sorry WA and NT…)

The ‘national’ energy market (from paper)

The ‘national’ energy market (from paper)

They looked at two different scenarios – the first one was rapid deployment of renewable technology with moderate electricity demand growth (ie. including energy efficiency gains), and the second one was moderate deployment of renewable technology with high demand growth (no efficiency gains).

They ran both scenarios for getting our act together by 2030 and procrastinating until 2050 to see what might happen.

Given that this is a government document, it comes with many caveats (of course!). There are uncertainties (always); CSIRO says bioenergy is feasible, other groups say it’s not that feasible. The costs don’t include transitional factors (and change over time), the costs of land acquisition or stranded fossil fuel assets and infrastructure. Phew.

They also pointed out the obvious (someone has to say it I guess) that because this is looking at 100% renewable electricity it does not look at nuclear, natural gas or coal with carbon capture and storage. This is a fossil free zone people!

Ok, so what did they look at? They took data from the 2012 Australian Technology Assessment by the Australian Government Bureau of Resources and Energy Economics, and using that looked at what demand might look like in 2030 and 2050, and calculated the approximate costs.

Their findings in a nutshell are that a renewable system needs more storage (you can’t put solar in a pile like coal to burn later), is a more diverse and distributed system, needs an expanded transmission network and will be primarily driven in Australia by solar.

Depending on when Australia does it, it will cost somewhere between $219billion and $332billion dollars to build. No surprises that it’s cheaper to do it now, not to mention the stranded infrastructure and assets you save by starting the transition now. It’s cheaper after all not to build the coal terminal if you’re only going to use it for a short period of time.

Cost calculations for Scenario 1 (rapid deployment) and Scenario 2 (moderate deployment) (from paper)

Cost calculations for Scenario 1 (rapid deployment) and Scenario 2 (moderate deployment) (from paper)

They included energy consumption by electric vehicles (EVs) as well as the reduction of demand from rooftop solar. Interestingly, rooftop solar will dramatically change the makeup of a national energy grid. Currently the energy grid is summer peaking, which means more power is used in summer (for things like air conditioners when it’s seriously hot outside). With the uptake of rooftop solar, the grid will become winter peaking, because demand decreases in summer when everyone’s solar panels are doing great.

They ran the numbers to make sure a renewable power grid is as reliable as the current power grid, which is 99.998% reliable, and made sure the technologies they picked are either currently commercially available, or projected to be available soon.

They found that the capital costs are the main factor, given that once renewable power is installed; it costs almost nothing to run, because you don’t have to feed it fossil fuels to go. There are maintenance costs, but all power stations have maintenance costs.

Storage capacity wasn’t found to be economically viable with batteries once scaled up, given that a renewable grid needs 100-130% excess capacity. So storage would be in solar thermal, pumped hydro, biogas or biomass. The paper noted that geothermal (which Australia has a fair bit of) and biomass are similar to current standard baseload power in the way they can be used. Concentrated solar thermal is still a new technology that is being developed, so the scale up potential is not fully known yet, but it’s working well in Spain so far.

The space required to do this (to put the solar panels on and the wind turbines in) is between 2,400 – 5,000km2 which is small change in a country that has 7.7mill km2 and is mostly desert. So people won’t need to worry about wind turbines being put forcibly in their backyards, unless they want them (can I have one? They’re pretty!).

The most economic spread of renewables for transmission costs was a combination of remote with higher transmission costs and local with lower energy generation capacity.

Transmission possibilities (from paper)

Transmission possibilities (from paper)

The sticking point was meeting evening demand – when everyone comes home from work and turns the lights on and starts cooking dinner and plugs in their EV in the garage. The paper pointed out that work-based charging stations could promote charging your car during the day, but also ran scenarios where the demand shortfall could be met by biogas. This also applied for weeks where the storage capacity of the renewables was low (a week of low wind or a week of overcast weather).

Meeting demand shortfall by dispatching biogas and biomass (from paper)

Meeting demand shortfall by dispatching biogas and biomass (from paper)

Long story short, the future is hybrid renewable systems.

Breakdown of each technology for the different scenarios (from paper)

Breakdown of each technology for the different scenarios (from paper)

There is no single technology that can replace the energy density of fossil fuels, but a hybrid grid can. Diversifying both the technology and geography of the power grid will not only allow for 100% renewable generation, it will also build resilience.

As climate change extreme weather events become more common, having a distributed power system will avoid mass blackouts. It will be better for everyone’s health (living near a coal mine or a coal power station is NOT good for your health) and it will slow the rate at which we’re cooking the planet. Sounds good to me.

Renewable Reality: Feasible and Inexpensive

Posted on by
2

‘Aiming for 90% or more renewable energy in 2030 in order to achieve climate change targets of 80-90% reduction of CO2 from the power sector leads to economic savings, not costs.’

WHO: Cory Budischak, Department of Electrical and Computer Engineering, University of Delaware, Newark, Department of Energy Management, Delaware Technical Community College, Newark, USA
DeAnna Sewell, Heather Thomson, Dana E. Veron, Center for Carbon-Free Power Integration, School of Marine Science and Policy, College of Earth Ocean and Environment, University of Delaware, Newark, USA
Leon Mach, Energy and Environmental Policy Program, College of Engineering, University of Delaware, Newark, USA
Willett Kempton, Department of Electrical and Computer Engineering, University of Delaware, Newark, Center for Carbon-Free Power Integration, School of Marine Science and Policy, College of Earth Ocean and Environment, University of Delaware, Newark USA, Center for Electric Technology, DTU Elektro, Danmarks Tekniske Universitet, Lungby, Denmark

WHAT: Working out how you could power a region with renewable electricity and the cost of doing it

WHEN: 11 October 2012

WHERE: Journal of Power Sources, 225, 2013

TITLE: Cost-minimized combinations of wind power, solar power and electrochemical storage, powering the grid up to 99.9% of the time

This research from the US is quite practical. The researchers looked at the electricity use from 1999 – 2002 in the ‘PJM Interconnection’ which is a power grid in the North Eastern USA that includes Delaware, New Jersey, Pennsylvania, Virginia, West Virginia, Ohio and parts of Indiana, Illinois and Michigan.

They wanted to know what a renewable power grid would look like, how much it would cost and how you could do it. Research excitement!

The PJM Interconnection power grid area in the blue lines. Pink stars are the meteorological data sites (from paper)

The PJM Interconnection power grid area in the blue lines.
Pink stars are the meteorological data sites (from paper)

So what does a renewable power grid look like in this area? It involves a combination of renewables, which are onshore wind, offshore wind and solar in multiple locations which provides the greatest range of renewable power sources (if the wind is still in one state, it may be blowing in the next state).

The first hurdle this team had to jump was storage. The most popular storage model for renewables is wind-hydro hybrids (which I’ve written about previously here), however in this corner of the USA, there’s not much hydro power. So the paper looked at the options of electric vehicle grid storage, hydrogen storage and battery storage (lithium titanate batteries for those playing at home).

They used the data from 1999-2002 to model the hourly fluctuations of electricity demand, which averaged out at 31.5 Gigawatts (GW) of 72GW of generation. They then matched the load hour by hour with renewables and worked out which was cheapest.

They calculated the costs with a level playing field, which means no subsidies. No subsidies for renewables, but also a magical time when there’s not billions upon billions of dollars each year for fossil fuel subsides as well.

The results were that a renewable grid with 30% of coverage produced 50% of the power required for the sample years, while a renewable grid that provided 90% of the power coverage produced double the power required and a renewable grid that provided 99.9% of the power coverage produced three times the energy required. The researchers found that an overproduction of renewable electricity was preferable to trying to exactly match the power required and also reduced the need for storage.

A few of the benefits they found were that offshore wind and solar often generate when inland wind doesn’t, and that there was greater over-supply of power in the winter months which could allow for natural gas heating to be replaced by renewable electric heating.

Renewable power in the 99.9% model only needed fossil fuel back up 5 times in 4 years (from paper)

Renewable power in the 99.9% model only needed fossil fuel back up 5 times in 4 years (from paper)

What about the costs? The researchers looked at what the cost was for power in 2010 dollars and then adjusted for efficiencies to estimate the 2030 cost of power for the model and the infrastructure.

The 2010 cost of power was 17c per Kilowatt hour (kWh), while a renewable grid with 30% coverage would cost 10-11c per kWh, a 90% renewable grid would cost 6c per kWh and a 99.9% renewable grid is at parity with the fossil fuel grid at 17c per kWh.

The reason the 99.9% cost is higher than 90% is because filling the gap of that final 9.9% requires more infrastructure to further diversify the grid, but I think the most important thing they found in their research is this:

‘The second policy observation is that aiming for 90% or more renewable energy in 2030, in order to achieve climate change targets of 80%-90% reduction of CO2 from the power sector, leads to economic savings, not costs.’

Yes, even in coal country in the USA, switching to a hybrid renewable system (in a level playing field) is cheaper than the current cost of fossil fuel electricity. It also comes with the added benefits of no mercury poisoning from coal fired power plants too!

The paper concludes that while excess power generation in a renewable grid is a new idea, it shouldn’t be too problematic since it saves on storage needs and is the most cost-effective variation.

Their advice for plucky leaders who would like to make this grid a reality? The most cost-effective way to build this grid is to aim for 30% renewables now, and phase in the rest to 90% in 2030. Each step along the way to more renewable power will not only be a climate saving step, it will save money as well.

Renewable Hybrid Systems: Optimising Power Grids

Image

1

WHO: Robert Huva, Roger Dargaville and Simon Caine

WHAT: Electrical power grids powered by renewable energy

WHEN: Published in Energy [41 (2012) 326-334]. April 2012

WHERE:  Earth Sciences department, The University of Melbourne, Melbourne, Australia

TITLE:  Prototype large-scale renewable energy system optimisation for Victoria, Australia (subs required)

One of the major barriers to the full scale take-up of renewable energy to power electricity grids has been the need to provide baseload power to users. This is the power required to keep your fridge running through the night, the power to keep traffic lights running all day and night and many other things. It’s the minimum amount of electricity required to keep the modern world running.

Renewable power is not constant, because the sun doesn’t shine at night and it’s not always windy, and water runs through rivers at different speeds depending on the time of year. So in order to provide the constant power needed, a hybrid system of renewable energy sources needs to be used.

This paper from the University of Melbourne in Australia has done that. They used detailed weather maps for the state of Victoria to determine the best locations for solar and wind power.

Victoria, Australia (Google maps)

Best locations for wind (blue) and solar (red)

They then combined the outputs of the solar and the wind with other forms of renewable energy, including hydro-electricity (running water spinning a turbine to make power) and wind-hydro hybrids where excess wind power will pump water up a hill to a raised dam, and when the wind dies down, the dam gets opened and the hydro starts producing electricity.

They found that the entire electricity needs of the state of Victoria could be met from renewable power sources with only 2% back up from natural gas needed.

 Hybrid renewable systems – meeting demand

So what does this mean for reducing the effects of climate change?

It means that renewable power is viable in the state of Victoria, which will allow the state to switch from it’s current power source of brown coal (which is much dirtier than your standard black coal when it burns, releasing more carbon pollution into the atmosphere).

Making the transition to a hybrid renewable system will also significantly reduce carbon emissions in the state of Victoria since 49% of energy in the state comes from coal power. It will create a large number of new jobs, as the renewable energy market increases from 12% (in 2011) to the 98% that has been shown in the research, which we will need to do in the next 30 years if we want to avoid catastrophic climate change.

How can it be done? By ensuring areas are able to access either localised power production (in rural or remote areas), or smart grids (in cities) that are able to monitor and respond to changing power production levels and changing energy use levels, hybrid systems of renewable electricity are fully capable of providing the power we need to run our lives.

*Full disclosure: The name is not a coincidence – this research was conducted by my brother as part of his PhD research (yes, I’m using my brother’s research to test out my own blog 🙂 )