Jordan O'BrienThe smart home is increasingly becoming a reality. From internet enabled dishwashers, fridges and washing machines, to apps that allow us to control the heating, air-conditioning and even monitor home security from our smartphones, it’s all ever more in our grasp.
Underpinning the whole concept of the smart home is power, and more importantly, how we install, store and use it to get the right return on our investment.
In the UK, Solar started for Sharp in 2004, with some iconic projects including the renovation of the CIS Tower in Manchester, where PV panels were used as a cladding material, creating what was, at the time, the largest commercial solar façade in Europe. Our solar business increased from 2008 with the rise of the feed-in tariff system that worked as an incentive to get solar onto the roofs of many homes across Europe. However, as PV prices drop, and as feed-in tariffs drop away, installers are looking for new ways of approaching their existing customer base, and are also looking for new ways of selling into a market that is moving away from an investment model to one based on self-consumption.
For many, the solution is to add battery storage to the solar equation. Sharp has seen sales grown considerably, almost doubling month on month, offering battery solutions from long-term partners, such as BMZ and Samsung.
The benefits of adding storage to the home solar solution is to take the average energy consumption rate, which is typically 20-30% a day, up to about 70-80% giving home owners maximum return on their investment and the option of greater independence from the grid. This is achieved by using the stored energy generated during the day, either at night or for other daytime loads.
Battery Size And Capacity
For the solar installer there are a range of factors to take into account. For instance, there are two main battery types, Lead-acid and Lithium-ion. Both have their own advantages and disadvantages.
Lead-acid is an older, heavier, technology that is well tested and highly reliable. It tends to be more popular on the continent than in the UK, where the property sizes are larger and where PV systems tend to be bigger.
An issue to take into account when suggesting Lead-acid batteries is they need regular maintenance. Batteries need to be stored in an appropriate room with plenty of ventilation and acid levels need to be checked on a regular basis.
Lithium-ion is a newer technology, smaller and self-contained and more commonly found in mobile devices, such as laptops and phones. It is slightly more expensive but is the preferred solution, making up over 90% of the UK market.
Along with being a sealed unit, Lithium-ion allows you to reduce the amount of space it takes up. And because of its high ‘ Depth of Discharge’ (DoD), users can enjoy a higher share of the battery capacity.
While Lead-acid batteries are mostly driven by a DoD of 50% – so you can only use half of the total battery capacity – the Lithium-ion DoD’s are up to 90-95%. So, if you have 10kWh of storage you can take nine usable hours with a power of 1kW.
When discussing battery capabilities with customers, battery capacities need to be considered. After all, we don’t want people being sold larger capacities than they actually require.
If you look at the average PV residential installation in the UK, they are typically from 2.6kWp (kilo watt peak) up to 4kWp in size. For every 1kWp installed, in the UK you’re probably going to generate around 800 – 900kWh per year, depending on where you are in the country.
There is a risk that some users can over-size their battery and never fully charge it, therefore paying a premium for something that isn’t going to be used. On average in the UK, you are going to use between 20-30% of the electricity generated, so when you’re sizing a battery you want to take into consideration your usage during the day and that you can physically fully charge the battery.
Installers also need to educate end-users on the typical life span of the batteries they offer. At the moment, batteries have a life span of between 3000 and 4000 cycles at the low end up to 5000-10,000 cycles at the high end.
A Return On Your Investment
Solar is in a great place right now but it needs installers to train and educate themselves not only on how to install the devices, but also how to sell the benefits to their customers in general. It is important the correct message is sent to the end-user and as such Sharp has set up a scheme that offers training on a range of solar topics including the installation and maintenance of battery systems. That can all be registered through the Sharp website.
When talking to customers about opting for solar PV, the question everyone comes to is one of payback. Yes, there is an upfront capital cost that will take between eight and 12 years to pay for itself, but people don’t consider this when they install double-glazing or add a new boiler to their home – it’s a mindset we need to change.
Solar isn’t about investment, it’s about cost of ownership. You may have an upfront cost but while it’s an initial cost, it’s fixing electricity prices for a period of some 20 years. While electricity prices have dropped at the moment, this is expected to be short-term and over the next 20 years we’ll see electricity prices increasing again.
Add to this other factors, such as reducing emissions, creating a greener environment and even long term energy security and you can see there is true value to adding a system to the home.
The Future For Solar Battery Storage
So far we’ve looked at storage in terms of the battery, but it’s simply that – a battery. It can’t do anything without intelligence. The smart home of the future will have ‘Smart Ready’ white and brown devices such as dishwashers, washing machines and fridges accessing and using smart apps to communicate with your battery, and control when and how appliances are managed.
We’re increasingly seeing smart apps that can add on a host of extra features, such wind, security cameras, hot water, central heating and water tanks and control them all from one simple interface.
Many devices offer limited connectivity options to other Smart Home products, and Sharp has therefore developed its own system called Smart Chap which is an open platform, able to work not only with many different batteries types, but also with heat pumps, air conditioning, measurement tools (meters) and switchable plugs. Sharp plans to continuously expand the feature set of the Smart Chap platform using its resources at the Sharp Laboratories in Oxford, and whilst individual users are not yet able to write their own programming, it’s hoped that further developments to the system will enable the breakdown of the energy consumption of the most widely used equipment in the home, to pinpoint the worst offending “power guzzlers” and help users to identify energy-saving potentials.
Such solutions come as desktop tools as well as mobile apps and are customer friendly for the end-user. They are clever enough that they are connected to the internet and monitor the weather as well, giving end-users the flexibility to see and control the system from their smartphone or tablet, where ever they are.
The app allows users to see how much electricity the roof-top solar system is currently producing, feed and take from the grid, the battery charge status and the current energy requirements of the home. The energy manager also displays how much and at which time of the day self-generated energy is being used, as well as measuring the energy performance of the home and how this can be improved. All of this data is saved and can be represented in graphs or charts for easy evaluation on a daily, monthly or yearly basis.
A major challenge when it comes to maximising domestic consumption of self-produced solar electricity is to get around the fact that solar energy is only produced during the day, yet is increasingly required in households when the sun is no longer shining. Controlling energy storage is a way to solve this problem and make solar energy available in the home right around the clock.
To address this, the “Smart Chap” app can also be used for the targeted control of energy storage, the feeding of energy into the public grid and energy consumption. It also allows users to control power-consuming devices via a wireless electric socket.
For the installer, such innovative apps allow them to monitor the machine, remotely if necessary, so they can check the health of the system, get a report and check all the storage units in case there are any potential issues.
Ultimately, when it comes to home energy storage and the smart home we’ll see that the battery is merely one piece, helping you balance the energy you generate with your solar PV panels, the energy you take from the grid, and that take from other energy devices all come into the mix. It is then the role of the intelligence smart app to monitor all systems and take the power from whichever source is most appropriate given the situation – that’s where the real future is.