NZEB + EV: The decarb combo

Are you aware of these stats?

  1. Buildings account for 40 % of energy consumption and 36 % of energy emissions (EU data)
  2. Road transport accounts for 25 % of energy consumption and 20 % of energy emissions (EU data and EU stats)

Then, what happens when we combine NZEB buildings (net Zero Energy Buildings) with local renewable generation and EVs (Electric Vehicles) charging in these NZEB?

NZEB & EV.png

It’s obvious… -> We can decarbonize 65 % of the energy system!* Sigue leyendo

Upcycling sun-tennas

The following picture was taken in Casablanca from the Kenzi Tower one month ago. It isn’t the best example, though, for example, in Cairo, it strikes more to the eye.

What do you see?…

Antenas techo

Actually, there are approximately 200 TV antennas on the roof-tops. Let’s zoom in a bit:

Antennas 25 In this portion, corresponding to one building alone, you have around 25 units.

With the advent of cable television, wireless video streaming and other technology, these antennas could soon become stranded assets in many countries. Imagine how many could be left useless and need recycling. While thinking about asset utilization and the sharing economy, I couldn’t help but think:

What can they be used for instead?… Sigue leyendo

Bono social y pobreza energética

El pasado domingo 13 de diciembre el programa Salvados #encasadeElisa estuvo dedicado a la pobreza energética.

Por qué es este tema relevante?

Es un problema que ha crecido un 69% en España en los últimos 4 años según el INE, aunque el Ministro de Industria no estaba enterado. Para Jose Manuel Soria, además parece que la única manera de combatirla, junto con reducir el paro, es el bono social. Como escribió Fernando Ferrando sobre el mismo tema, quien no puede pagar, aunque le hagan un 25% de descuento, sigue sin poder. Además, aunque el consumo energético eléctrico es mucho menor que el consumo de gasolina y representa una parte pequeña del consumo familiar (como planteaba en mi post sobre electrificar el transporte) no es el caso de las personas en situación de pobreza energética. Para ellos, obviamente supone una parte mucho más importante, compitiendo con la comida por el dinero disponible.


Calefactor eléctrico. Imagen de Gabriel Fernandes en


A pesar de reconocer que el bono social está mal planteado, el (hasta dentro de poco) ministro de industria no mostró ninguna intención de mejorarlo. En el mismo programa, al menos el ex-ministro Sebastián planteó la opción de que un consumo mínimo debería ser gratuito, puesto que la energía es un bien de primera necesidad.

Cómo se podría modificar el bono social y la tarifa eléctrica?

Sigue leyendo

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:

Sigue leyendo

From 0 to 5-star Microgrids

Every building, office or home is a microgrid.

The question is, how good a microgrid do you want it to be?

Here is a simple 5-star rating for microgrids, an approach for anyone to understand;

You get one star for adding each of the following technologies:

1. Control

2. Generation

3. Electric Vehicle charging

4. Energy Storage

5. Microgrid Islanding functionality

Star Microgrid

A normal 0-star microgrid is a conventional building or home, with no automation or else.

It happens you upgraded your home and installed a smart thermostat for electric heating/cooling? Sigue leyendo

Take the panel with you

Solar Panels are getting cheaper every day, so this idea might convince you less today than it could have some time ago…

Anyway, suppose you have bought yourself one 300 W solar panel for your flat. In fact you found a smart orientation that covers your “base load” for the fridge and all the stand-by consumption and also lowers your consumption once you arrive home. It happens you have a e-bike that is prepared for you to plug your panel, for your daily commuting, keeping your battery fine or even charging while you are working. Additionally, you own an Electric Vehicle. During the week-ends, you can dock your panel for the journey and lower your consumption. And it happens that you are as wealthy as to have a second house in the forest, which is off-grid, so you use the battery of the Electric Vehicle for your consumption and you also plug your panel when you arrive.

Panel cycle

This is just an example of maximizing the asset utilization of a panel, for house self-consumption in two locations, and also for mobility. This will not be the case for most people, of course. Besides, regulatory frameworks may promote the use of the panel to feed the grid when it would be underused only for self-consumption and could be connected elsewhere for other purposes. Anyhow, the point of having portable generation opens more possibilities for generating one’s own energy, in this case at home and also for transportation. It is also an application for extending the access to electricity in developing countries.

In fact, if a person consumes (as it is the case in Spain) 3487 kWh/year of electricity and 9908 kWh of total energy at the home, together with 12000 km/year of driving, which can be calculated as 2400 kWh (with an EV doing 20 kWh/100 km) it makes a total of 12308 kWh. In order to source this with solar PV, he would need approximately 6 kW of solar panels working 2000 equivalent hours. These 20 solar panels he cannot take around with him that easily. For the moment…

P.S.: Allow me to include the crowded house video as the song I thought about while writing…

Demand energy policy Vs supply; the Saudi Case

In my opinion, there is no better example of where demand energy policy is pivotal than in the KSA (Kingdom of Saudi Arabia).

In KSA, peak demand is expected to nearly triple from 44 GW in 2010, up to 121 GW, in 2035 (Source: ECRA 2010). This is, of course, with the actual demand patterns and expected growth.

The supply energy policy takes these predictions as valid and focuses in covering the expected demand. How is it planned in the KSA case? By building 41 GW solar plants and 21 GW of nuclear, geothermal and waste-to-energy (source: KACARE, Saudi Solar Energy forum 2012). The lead time for building the capacity (specially in the case of nuclear) is difficult to synchronize with the aggregate demand behavior, and there can be frictions. An example of supply energy policy going wrong is that of Spain, where current excess power generation capacity has been (mainly) a consequence of decreasing demand opposed to predicted growth.

However, if we take a look at the demand (source: Saudi HVAC confex), the HVAC represents more than 70% of electricity consumption.

Cooling % in KSA

Given the importance of HVAC, we might agree that the first Saudi HVAC conference, should have taken place sooner than start of this year (February 2013)

Demand energy policy focuses, instead of building GWs of nuclear power to generate, transport, distribute and transform into cooling, in reducing the expected growth in demand. Solutions are building retrofits, HVAC efficiency improvements, renewable self-consumption, solar cooling, etc. Deferred investments in generating capacity are the best return on investment for these energy efficiency and demand response measures.

In fact, during the recent WEC (World Energy Congress), the SEC  Eng. Ali Saleh Al Barrak, President and CEO , highlighted the building retrofit as offering the biggest opportunities. That’s not only true for KSA, Spain, again an example, has a great opportunity in building retrofits to improve energy efficiency and reactivate the building industry.

Moreover, a 2012 paper on efficiency measures, described the opportunity for the future of the KSA, both on supply and demand:

In short, both demand and supply policies have to be considered, but in my opinion, demand measures are more sustainable, more efficient, faster to deploy and have a better return on investment. We’ll see what Saudi does…