Baseload, Hydropower, Project Development, Storage, Wind Power

Combining Wind and Hydro — How to Ensure the Renewable Bubble Doesn’t Burst

Last year, a record-breaking 147 GW of power globally came from renewable sources. If we’re to continue this trend — especially in the light of the COP21 agreement, and recently concluded COP22 — we need to ensure renewable energy is as reliable and accessible as possible.

From a policy perspective, we can attribute some of the steps forward to the continuous cost-reduction of renewable energy, which is moving us ever closer to a subsidy-free environment. However, one thing we can’t control with any amount of policy making is the weather: it is totally beyond our control.

Of course, intelligent location planning can mitigate these issues but, ultimately, if the wind doesn’t blow, the rain doesn’t fall and the sun doesn’t shine, we are powerless. Quite literally.

Relying on a sole source of renewable energy limits our options. Instead we should look to use innovative technology to combine multiple sources to tackle the challenge of unpredictable energy output.

Introducing Hydro & Water

On their own, wind and rain can be unpredictable. Factors such as the strength of the wind and the amount of rainfall directly impact how much power is produced. However, if infrastructure for both hydro and wind are placed on the same site, you can consolidate the two into one grid connection and manage the power generated from each.

Logistically, this makes perfect sense. If both renewable sources are placed into the same grid connection, it becomes much easier to supplement one with the other. So, for example, if there’s a day when the wind isn’t blowing, you can use water from pumped storage to generate electricity and vice versa. That said, combining hydro with wind is not without its challenges.

Geographic Challenge

The main challenge with combining wind and hydro on one site is a geographical one. You need to find the right location which can house the infrastructure needed for both a wind farm and — depending on the type of hydro site needed — either a large water source, or space for reservoirs.

There are two types of hydro sites. The first is the traditional hydro power plant, which would mean the site would need to have an existing water source large enough to be used for power generation. It would also require enough land with the right climate to house a wind farm. The chances of finding a location suitable for both are slim, but possible.

The other type is a pumped storage solution, which doesn’t rely on a natural source of water but instead requires two reservoirs which hold rainwater. While this type may be more dependent on rainfall, it does make the search for land much less difficult.

To minimize the construction time, you could look at existing hydro plants and evaluate their suitability for a wind farm expansion. You could also do this in reverse and see if any wind farms have a suitable water source nearby. Alternatively, you could look for sites which have nearby decommissioned mines, which could be converted into the low reservoir. That would mean that only the wind farm and elevated reservoir would need to be built, saving significant costs.

New Kind of Management

Another challenge is pricing and how the market will respond. Such a hybrid renewable model is still very much in the early phases of development, so pricing needs to be looked at carefully, as does market behavior.

This new model of renewable energy will raise several questions about regulation, policy, and ownership. Will it fall under the grid’s jurisdiction, or will it be under government control, or privately owned? And how will it be priced? These are all questions which need to be answered before it can be rolled out more widely, and can become potential obstacles causing project delays and slowing a nation’s energy agenda.

However, this new kind of energy production also put a spotlight on the multi-asset management. At present, electricity is sold to the grid at different rates depending on several factors, such as time of day and demand. As it enables the same operator who oversees different plants to maximize energy output across sites and profits depending on prices and weather conditions, it can provide further incentives to make this model a reality.

Going Digital

Once the various location and market challenges have been addressed, the next stage will be tying wind and hydro together for the most efficient, green and reliable power production possible. One of the key enablers will be digital solutions.

Transforming the infrastructure using connected devices will provide a number of benefits. It will allow for real-time control and monitoring, enabling engineers and operators to remotely diagnose and fix faults faster. Advanced weather forecasting can also help predict power output for the coming weeks. This will help operators make informed decisions that can optimize output, switching between wind and hydro. For example, if it looks like the wind isn’t going to be blowing strongly enough, they can choose to pump and store water in preparation. Predictive analytics also enable them to spot potential equipment failures before they occur.

The future also holds exciting prospects in terms of big data. Bringing your infrastructure online means that you can build big data models, which in the future could automate the plants and farms, reducing costs even further.

Looking to the Future

We see the future of renewable energy being based on combinations of multiple renewable sources. It is one of the most effective ways to mitigate the problem of unpredictable renewable generation.

Other than wind and hydro, other combinations are possible, depending entirely on the region and its needs. For example, for places that suffer from heavy droughts or have inconsistent bouts of rainfall, another solution is to combine solar with hydro. This option would involve using solar as the baseload during the day, storing water in the reservoir, then switching to hydro power during the night when the sun isn’t shining.

There is no one-size-fits-all solution as every location is different. Ultimately, what is important is securing a bright, sustainable and reliable future of renewable energy.

Another element to this is the multi-site model, where one large plant can provide the baseload for a wide area, while smaller renewable sites top that up. This would allow developers and operators to manage several different sites at once, ensure a holistic oversight while also maximizing profits and efficiency.

Site and asset management could also be made easier. In fact, engineers could explore the concept of storing water in the tubes of wind turbines. This has multiple benefits: it is much easier to find a site suitable for wind farms only, and it also saves space on the site, elevates the turbines so that they can capture more wind, all while making the solution repeatable.

Taking a Leap of Faith

The consolidation of two (or more) renewable sources into one site isn’t a traditional model, and is a bit of a leap of faith. However, if done right, it has the potential to change the way the industry looks at renewable energy.

With so many moving parts in this new machine, it is important to ensure you have a partner, such as GE, who has industrial expertise across energy spectrum, and who can handle all the issues that may be encountered, from financing to engineering and operation and maintenance.

Although there may be many questions which are yet to be answered, it’s certainly an exciting time in the industry as we move towards the next golden age of energy.