In order to meet the UK's commitment to reduce 80% of greenhouse gas emissions by 2050, it is necessary make major advances in efficient, clean and secure energy conversion and use. Thermoelectric materials are of interest because they are able to take advantage of wasted or unutilized heat sources, such as in furnaces, car exhausts, and solar cells. These materials are able to convert a temperature gradient into electrical power, and vice versa without mechanical intervention. We have produced ligated silicon nanoparticles that show great potential as thermoelectric materials. Our measurements up to date are bulk measurements of properties of interest such as electrical conduction. In order to improve these materials by design, it is essential to know the microscopic conduction rates and mechanisms. Muons as local probes provide the best way of measuring these important properties.