Bicycles in Amsterdam

Last year I was in Amsterdam and was intrigued by their bicycle culture, so I took a few photographs. To tell you more about Amsterdam’s bikes, here are some headlines from “19 interesting facts about bicycles in Amsterdam” (Amsterdam Hangout, September 2019): 

– 1. There are over 881,000 bikes in Amsterdam. 

– 2. The number of bikes is four times the number of cars. 

– 3. Statistically, each resident of Amsterdam owns at least 1.5 bikes.

 – 4. The most popular type of bicycle on Amsterdam’s streets is the traditional Omafjets (see blue bike in photos). 

– 5. 35% of trips daily in Amsterdam are by bike. 

– 6. 60% of Amsterdammers use their bike every day. 

– 10. Amsterdam has a wide network of traffic-calmed streets. 

– 13. Amsterdam has currently over 400 kilometers of bicycle paths. (Read more from the hyperlink above.)

Can “solar hydro" replace coal and gas-fired power stations?

Organic Rankine Cycle (Source: Applied Sciences, 9 (1) 49, 2019)

RayGen, with the support of AREA (Australian Renewable Energy Agency) and in collaboration with other companies, is on-track to test a 50MWh “solar hydro” project in NW Victoria. The plan is to eventually develop a 200MW solar power plant with around 100MW/1000MWh storage. This is enough to help replace retiring coal and gas fired power stations.

The plant will consist of mechanical mirrors on the ground concentrating sunlight and heat to RayGen’s efficient collector on a raised tower. The collector consists of mirrors and super-efficient PV modules which can collect both light and heat. The specialist panels convert about 30 per cent of the sunlight to electricity and capture around 60 percent of the excess heat. 

The heat is stored as hot (92^°C) water in one reservoir while the electricity is used to chill water to 2^°C, which is stored in a cold reservoir. Between the two tanks is the Organic Rankine Cycle system (see above diagram), which has a special organic fluid circling within it. At the evaporator, the fluid is heated to a gas by the stored hot water which then drives a turbine to generate electricity. The organic gas then passes to the condenser where it is cooled back to a liquid by the stored cold water. 

With the organic fluid coming to boil at a lower temperature than water, it means that the system has a high efficiency. Since the water temperature differences are stored like a battery in the reservoirs, the system can generate electricity when required. “The temperature difference of about 90^°C has a similar energy storage capacity as pumped hydro with a height of 1000 metres – so really, really big pumped hydro.” says RayGen’s Will Mosley. “RayGen is able to deliver the economics of pumped hydro and the flexibility of batteries.” (RenewEconomy) 

Read more: 
- RayGen edges closer to “solar hydro” success with new strategic partnerships. RenewEconomy, April 16, 2020. 
- World-leading solar technology born in Melbourne, that’s ultra-cool. ARENAWire, September 28, 2017. 
- Solar power plant phase 1. ARENA, January 2020. 
- Renewable energy storage, solar power technology. RayGen

Renewable fuels from direct air capture could soon compete with petrol, diesel, jet fuel

Source: RenewEconomy

It may soon be possible to produced zero-emission petrol (gasoline), diesel and jet fuel from the direct air capture of CO2 and water vapour in a way that will compete with fossil fuels in price. A Silicon Valley company called Prometheus led by Rob McGinnis is aiming to do this. The process has been presented recently in the journal Joule. 

Although the science of making fuels from CO2 and water has been known for some time it has been far too expensive. The Prometheus process has CO2 and water in an aqueous electrolyte which is reacted with a copper catalyst to directly make alcohols such as ethanol, butanol, propanol, etc. with the power coming from wind and/or solar electricity. Originally, the alcohols would be extracted via distillation, which is expensive, but Prometheus has invented a carbon nanotube membrane that can do this economically. (Launch HN, 2019). 

This fuel can be used with existing infrastructure for cars, trucks, ships and aeroplanes, so can be employed quickly. It is not seen as a replacement of electric or hydrogen transport but as an addition to help speed up the transition to clean transport, particularly for heavy transport. Once the green fuel is cost competitive there is still one main drawback and that is that huge amounts of renewable electricity will be required. But one advantage is that the process can be stopped and started easily to fit in with the fluctuations in electricity supplies and costs (i.e. it would be another way to store excess renewable energy). 

References: 

- Prometheus: https://www.prometheusfuels.com/ 

- Remove CO₂ from air and turn it into gasoline. Launch HN: Prometheus (YC W19). 

- Renewable fuels could soon be cost competitive with petrol, gasoline, RenewEconomy, March 19, 2020. 

- CO₂-to-fuels: renewable gasoline and jet fuel can soon be price competitive with fossils fuels, Joule, Commentary, Vol. 4, Iss. 3, pp 509-511, March 18, 2020.

Big batteries may soon play a major role in Australia’s main grid

Ballarat's big battery (Source: RenewEconomy)

Stand-alone big batteries may soon be playing a critical role in eastern Australia’s massive electricity grid as recommended by the Australian Energy Regulator recently. The grid needs major upgrades as it transitions to a clean energy future.

The big batteries have been in Australia for less than three years with the big Hornsdale Tesla battery starting the trend and showing us that these batteries have many more features than just energy storage. This battery was followed by four others on the main grid at Lake Bonney, Dalrymple North, Gannawarra and Ballarat. 

These batteries have shown that they: allow the output of wind and solar to be “stored” and “firmed”; provide much needed competition in the frequency and ancillary services market; play a key role in grid security; reduce costs and improve reliability for off-grid iron ore mines; reduce overall grid costs; respond within milliseconds to power failures or peak demand; and cause power engineers to admit there is a smarter future than relying on ageing and slow responding coal generators (RenewEconomy).

Big batteries are therefore seen as ‘virtual transmission’ lines that can absorb excess solar and wind power at times of oversupply and instantly inject power at times of demand. This therefore reduces the need for extra poles and wires. Now they are ready for the next stage – playing a critical link in providing much-needed increased capacity between the various state grids. 

This is now the view of the Australian Energy Regulator, which has encouraged transmission companies to look into battery storage technologies as an option for the numerous grid upgrades that have been recommended by the Australian Energy Market Operator to ease the transition to a renewables-dominated grid. 

Read more: 

- “Big batteries get ready to play main role in next stage of clean energy transition.” RenewEconomy, April 1, 2020. 

- “Battery storage nearly there as smarter, cheaper choice for grid upgrades.” RenewEconomy, October 1, 2019.