Your Digital Self: I’m putting a solar array on my home. Here’s what I found out about the technology, storage and cost
We’re facing an energy crisis. Demand for oil and gas is increasing, outpacing supply. That, among other factors, has contributed to a sharp increase in prices and has helped create a growing market for alternative-energy sources.
A promising alternative is solar power. It is clean, renewable and abundantly available. It also has the potential to meet global energy needs without causing pollution.
However, solar power is still relatively expensive and difficult to store, which is why it currently cannot compete with fossil fuels on a large scale. But as the technology is developed, solar power is becoming increasingly viable.
I finally decided to take the leap and install a solar-array system on a home I’m building. My goal was to have a standalone system that can fulfill all my energy needs — not only in the case of a blackout, but also throughout the year.
To make this happen, I reached out to Vivo Somnia, a Croatian company with 10 years of experience in the field. We discussed all the neat (and techy) details with CEO Edo Jerkić, legal expert Ana Marija Jakas and Ivan Szekeres, an electrical engineer working on my project.
We discussed not only my own specific project, but the general state of the industry. Here’s what I found out:
MarketWatch: As a future owner of an average urban home, is it possible to be 100% independent of government-supplied electricity?
Vivo Somnia: It is possible, but high prices are the biggest obstacle.
The initial installation cost of 100% off-grid or a hybrid solution — in addition to solar energy, a solar photovoltaic plant can interact with the grid as well as other backup energy sources — is still too high for an average Croatian [and American] household. If the goal is to be 100% energy independent and finances are an issue, one way to go about it would be to space out the investments into several standalone phases.
MW: What other energy sources would you advise?
VS: You can be 100% independent with just a solar system in combination with battery storage. The size of such a system largely depends on the household’s consumption needs and habits, as well as the climate in which the household is situated.
It is also important to note that achieving a level of energy independence while still being connected to the grid — those are the projects we mostly work on nowadays — is still the more cost-efficient solution.
Combining PV [photovoltaic solar panels] with small wind turbines is very convenient. However, the production output from turbines is significantly lower compared with PV, and the technological development has stalled. You can also use pellet fuel to heat your home, but nowadays a combination of PV and a heat pump is a more efficient and convenient solution.
MW: What are the most advanced systems that someone can buy today to make this kind of independence a reality?
VS: Today, the ideal home solution for 80% to 100% energy independence is a hybrid, smart energy system with photovoltaic panels, a hybrid inverter and a battery system with a battery backup. Also, the usage of heat pumps and EVs [electric vehicles] is recommended.
It is difficult to estimate the cost of one such system because it depends on several factors — location, energy consumption, local regulations and so on. But as an estimate, this should be anywhere between 15,000 euros ($16,525) and 25,000 euros ($27,560) for a 150-square-meter (1,614-square-foot) house. These are the costs for the European market.
MW: What about future developments in the sector? What can we expect in next five to 10 years?
VS: The consumer segment is focused on new technologies and new energy storage systems. We still expect that PVs will become more efficient and more affordable, although that trend is slowing. On the other hand, the development of new battery storage solutions is progressing rapidly. We can expect much cheaper battery systems with better efficiency. But most importantly, we will see new technologies which focus on replacing lithium-ion batteries with more sustainable solutions.
On the consumer market, the shift will be more socially- than technologically-oriented, and supported by more liberal electricity market legal frameworks.
MW: A growing number of consumers want to go off-grid and become self-sustainable as far as energy production is concerned. Do the EU regulations make this possible today?
VS: Recognizing the benefits of self-consumption, and the remaining barriers to overcome, the EU and its member states have sought to provide a framework and ensure that individuals are placed at the center of the energy transition and can contribute to Europe’s CO2 reduction targets. The EU’s Energy Union Strategy set out to enable consumers to take ownership of the energy transition and play an active role in decarbonizing Europe. Under the Energy Union, the EU updated its energy policy framework through the “Clean Energy for all Europeans” package, to create a new wave of “prosumers’.” In particular, the revisions of the Renewable Energy Directive and the Electricity Market Directive have set out provisions related to self-consumption. Under the Renewable Energy Directive, member states are required to ensure that consumers can become self-consumers.
Such systems are most often installed at locations where the connection to the electrical grid is unavailable or very expensive. The cost-effectiveness of the off-grid system is increasing every year, given the downward trend in equipment prices. In addition to buildings, these systems are used in maritime traffic, traffic signals and streetlights.
MW: Let’s talk about practical details. You’re designing and installing a system on my house. What kind of system would get me as close as possible to complete energy independence?
VS: Let’s start by providing initial parameters of energy consumption for your house:
Three-phase electric-grid connection 13.8kW (kilowatts)
Hot water, heating and cooling: three-phase heat pump
Backup heating system: wood-burning boiler
Electric energy consumption: 15,000kWh (kilowatt hours)
Based on these parameters, we will construct the following system:
15kWp (kilowatts peak) photovoltaic modules
10kW hybrid inverter Fronius GEN24 Plus 10.0, with a three-phase full backup function for the whole house
4kW hybrid inverter Fronius GEN24 Plus 4.0, with a one-phase backup function for additional backup if needed. (EV charging, for example.)
Battery-Box Premium HVM 22.1 for the Fronius GEN24 Plus 10.0 inverter
Battery-Box Premium HVM 11 for the Fronius GEN24 Plus 4.0 inverter
Home smart energy-management system
Three-phase backup solution for the heat pump. (Most hybrid inverters have a one-phase backup solution.)
Big yearly electric consumption of 15,000kWh and smaller energy production in winter. (This issue is solved by relying on a grid backup and wood-burning heating backup boiler.)
There you have it. My family is navigating an off-grid solution within the restraints of the local regulations. If you have any questions or would like to learn more about the process, reach out to me via Twitter, or simply watch out for the next article. After the house is built and solar system implemented, I will let you know just how close it has gotten me to true energy independence.