With the cost-of-living crisis families are struggling to keep the lights and the elderly are struggling to keep warm in winter. This is the reality facing people in the UK and across Europe as energy bills have surged. Most of the Swiss population live in rented apartments as do an increasing number in the UK, there is little chance they can take advantage of solar technology to help lower bills which in the last 12-18 months have doubled for many. We live in an increasingly urbanised world. In 2021, 38.9 % of the EU population were living in a city. Europe's level of urbanisation is expected to increase to approximately 83.7% in 2050\. This places a challenge on services, properties and local infrastructure. As more people live in apartments, due to the cost of rent and a squeeze on incomes, the strain on the energy network increases as local electricity demand increases. At the same time, the grid is already under strain. The UK aims to fully decarbonise the power sector by 2035 through the installation of renewable energy sources including wind and solar. The challenge with renewables is the intermittency of supply and matching that to demand. It requires a significant investment increase in grid infrastructure to cope with increasing urbanisation and the balancing of supply and demand of electricity. This project aims to develop cutting-edge home energy storage technology that will enable the installation of sophisticated, compact, movable battery systems in apartments and houses to smooth out the demand curves for consumers thereby reducing their bills by over 50%. Smart batteries could also provide a range of balancing services, primarily extra storage, for the grid to reduce costs and decarbonise the grid at a faster rate. The technology could reduce consumer electricity bills paid by 50% saving £1200 a year or more for a typical 4-person usage (based on typical usage data and current costs for electricity). This bi-lateral project between Allye in the UK, Negal in Switzerland, and OST, a Swiss research institute, will create a ultra-efficient bi-directional AC-DC converter using technology generated in Switzerland, plus a sophisticated battery system incorporating machine learning which will be designed and built in the UK, has the potential to bring down the cost of energy across the country with a specific focus on apartments and small homes (including renters), while helping to accelerate decarbonisation of the electricity grid.