Sailing 100% renewable

You might have read an old post on electric boats and sea energy harvesting before. I described then, electrifying boat transport as one of the ways to make islands 100% renewable.

Electric sailboats have a lot of sense, and are becoming more and more popular. It’s a fantastic sensation to sail, without the sound of a motor, and for many of us, turning the diesel engine on is to be avoided as much as possible. Moreover, even when the engine is only used for a little time, we strongly feel the pollution.

Precisely because for a sailboat the engine is not used that much, having electric propulsion and battery storage is very reasonable. It can be charged at the normal port outlet, regenerating while sailing, or with a small wind generator and solar panels. Compared to the need of refueling at a port gas-station, the convenience is increased greatly, and also the cost to the owner.

Maintenance of an electric motor is simpler because of less moving parts, the size of the motor is reduced, and the battery can be placed as ballast, incorporated in the hull. Sailboats already have batteries and often the motors have to run just to charge them. By increasing the size of the batteries and having renewable charging (solar/wind), this is automatically taken care of.

Besides, the performance is increased, having more torque at lower rpm, and electric motors are more efficient that the internal combustion counterparts.

Finally, regarding the noise, see this video comparing the diesel engines to electric. Together with the smoke/pollution, this is the most dramatic difference.

In summary, it will amaze me if in 5 or ten years all 95% of all new sailboats are electric. And I hope to sail on one of those soon.

20160730 Sunset desde barco

Sunset near Cala D’Or in Mallorca

If Energythaca were an island, sailing there would be on a sailboat. That was the image on my first post on the blog.

I guess it is an appropriate post arriving from vacations…

The grid as an emergency supply?

It’s official. Finally Spain has the most toll-intensive consumer power generation (what is called self-consumption) law in the world. The so-called “sun tax” is in place.

It is important to understand the worries of the regulator here;

Given the high fixed costs of the system, further reductions of electricity demand (as with self-consumption) increase the price of energy in a Grid independence cycle. The goal of increasing the toll on self-consumption is to ensure the system costs are covered, delay the implementation of self-consumption (starting in the islands and small systems), delay consumer energy storage (in fact it is also a “battery tax”) and (try to) avoid further political problems. Of course, it is not the best solution, academics and regulatory experts agree that politically fixed costs that have to be paid by all citizens shouldn’t be in the tariff but evenly paid from the nation’s bugdet (like the extra-costs for electricity in the islands).

Image by Cancia Leirissa on

“Grid Emergency Exit”                                                       Image by Cancia Leirissa on

What are the consequences? Rising prices, and the fact that fixed costs (for the contracted power) are surging, push the active consumer to look for the following solutions:

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Research article: Asessing Islanding Microgrids

The article we recently published, presents a method to assess the most appropriate microgrid configuration, depending on the costs of grid energy, renewable prices, storage, islanding conditions, etc:

Article Microgrids

Our definition of microgrid includes any network on household or building when including control, generation, storage or islanding capabilities. These microgrids must ask themselves what configuration is their best option, from full utility dependence to off-grid… The thing is: You ARE a microgrid, so what kind of microgrid is best for you to be?

Timer Plug off-grid TICTAC

Image from newkemall on

Actually, to turn every household and every residential, industrial or commercial building into a microgrid, with a Home – Building Energy Management system, with renewable generation (and storage) is the way of implementing the Smart Grid bottom-up and also Democratizing power generation.

It also pushes the system towards net-zero energy buildings which is the way forward pointed out by the EC, for example.

You also wonder what the Grid Independence Cycle is?

Read the article and take a look at Spain, where the menace for a toll on self-consumption and the fact that fixed costs are higher than variable costs may lead the system into the circle, with increasing partial or complete islanding (even with an additional toll, who knows) from the network.

Google energy storage

I’m surprised Google Energy has still not got it…

How did they create the most competitive data centres in the world to grow so fast? How could they build the most competitive energy storage centres in the world?*

If you know the answer to the first one, you probably know what I mean in the case of energy storage.

By Steve Jurvetson ( [CC-BY-2.0 (], via Wikimedia Commons

Google Production server. By Steve Jurvetson ( [CC-BY-2.0 (, via Wikimedia Commons

The key was and is to use inexpensive harware. With servers, rapid obsolescence meant they wouldn’t need to repair the PCs used for their servers, many of the servers wouldn’t ever work, and the design had to be optimized to work around these failures. Of course now they are interested in the most energy efficient server systems, as that is the main cost for operating data centres, but the cheap and fast concept remains.

In the case of battery storage, Sigue leyendo

Do we need batteries without wheels?

Let’s start this post by quoting another post on a recent market estimation by IMS research, estimating the battery energy storage is to skyrocket up 200 M$ today to 19 bn$ in 2017.

While this may look promising, and seem the perfect way to increase renewable penetration, paving the way to a decarbonized energy sector, please stop. …and reconsider if it is the best solution.

Why decarbonize the power sector alone… if we can decarbonize the transportation and the power sector at the same time?

Battery wheels

How? Investment in electric vehicles (EVs) must be economically efficient in itself (cheaper than the CO2 emmitting vehicles) so every € invested has already a return via mobility (for the owner/user). This means using the available storage is relatively “free” to the power sector. In my opinion, subsidizing  battery storage (gathering dust inside a building) is a stupid idea compared to incentivizing the “transport-sector-decarbonizing-storage” or, to say it other way, batteries-with-wheels. EVs should be incentivized not only by governments trying to reduce the energy sector trade unbalances and reducing CO2 emissions, but also by utilities willing to increase the customer’s bill (an EV customer is billed aprox. a 30% more)

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