Presentation Details
| Economic Evaluation and Deployment Feasibility of the PV-Ready Method in Wooden Apartment Buildings for Rent in Japan Ryoto Matsushita, Tomoko Iwata, Tsuyoshi Yoshioka. Shibaura Institute of Technology, Saitama, Japan |
Abstract
Achieving carbon neutrality by 2050 requires the widespread adoption of renewable energy in the residential sector. In Japan, rental apartment buildings account for approximately 40% of the housing stock; however, photovoltaic (PV) adoption in this segment remains limited. This is largely due to two structural barriers: the split-incentive problem between building owners and tenants, and the technical and financial challenges of retrofitting PV systems into existing buildings. While owners bear installation costs, the benefits of reduced electricity bills are primarily enjoyed by tenants. In addition, retrofitting often entails high costs and risks damaging building components. This study investigates the potential of a wiring-ready (Ready) method for wall-mounted PV, in which electrical conduits are pre-installed during the construction phase. This approach enables future PV installation at lower cost and with reduced physical impact, even when PV systems are not deployed immediately. Similar policies have been implemented in regions such as California, where Title 24 mandates PV- and battery-ready wiring in new residential buildings. A standard two-by-four wooden apartment building model was developed based on architectural and electrical drawings. Using a building information modeling (BIM) approach, multiple wiring routes were simulated to compare construction quantities and costs under Ready and non-Ready conditions. An investment feasibility analysis incorporating projected PV cost reductions was also conducted to evaluate economically optimal installation timing and the impact of the Ready method. The results indicate that the Ready method reduces retrofit costs and enables PV installation to become economically feasible earlier. These findings provide practical design insights for promoting PV adoption in rental housing and advancing residential-sector decarbonization in Japan.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.