Baterias en sistema fotovoltaico

A Study of the Merits of a Battery Combined Photovoltaic Generation System for a
Residential House
MASAHIDE YAMAGUCHI,1 ATSUSHI IGA,2 KAORU ISHIHARA,3 DAISHIRO WADA,4
KIYOAKI YOSHII,5 and OSAMU SUEDA5
1Japan Storage Battery Co., Ltd., Japan
2Takamatsu National College of Technology, Japan
3Komae Research Laboratory, CRIEPI, Japan
4Shikoku Research Institute Inc., Japan
5The University ofTokushima, Japan
SUMMARY
In this paper we examine the merits that a practical
photovoltaic system combining photovoltaic generation
with storage batteries would provide if used in ordinary
residences. Various configurations and operation methods
could be envisaged for such a system. In this research we
examined the optimal battery capacity, operation methods,
and economic effects for asystem emphasizing an economical
merit for the user. We first calculated the hourly
amount of photovoltaic generated electricity each month,
and used data on average load patterns from actual measurements
to calculate battery capacity. Next, taking battery
capacity and photovoltaic module capacity/price as parameters,
we calculated and evaluated the economic merit
for ordinary residences. Theresult showed that the optimal
battery capacity for combination with 3- or 5-kW photovoltaic
generation is around 10 kWh, and that a combined
system provides a merit even though it entails higher photovoltaic
module costs than the use of photovoltaic generation
alone. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn,
147(4): 20–31, 2004; Published online in Wiley Inter-
Science(www.interscience.wiley.com). DOI 10.1002/
eej.10302
Key words: photovoltaic generation system; photovoltaic
module; battery; combination system; economic
merit.
1. Introduction
Photovoltaic generation systems, especially for independent
houses, are now commonly used. There have been
studies of systems combining photovoltaic generation with
storage batteries [1–3], but their practical use andcommercialization
cannot be realized due to deficiencies in the
performance, lifetime, price, and so on, of storage batteries.
On the other hand, the performance of current storage
batteries has been greatly improved, the cost has been
significantly lowered, and related technologies have developed
greatly. Against this background, we have examined
a practical system that combines photovoltaicgeneration
with storage batteries.
To examine the system combining photovoltaic generation
with storage batteries (referred to below as a “combination
system”) for ordinary residences, the optimal
combination capacity and operation method differ according
to the purpose and features. That is, merits can be
divided into two categories as follows according to the
purpose and importance:
1 Economicmerit for power consumers (installers)
2 Load leveling merit for electrical enterprises
We examined the optimal capacity of the storage batteries
to be included, the economical effect, control method, and
so on, for systems with respect to the economic merit for
power consumers, then confirmed the viability of bringing
it into practical use.
In this paper we first describe how to calculatethe
hourly photovoltaic power output in each month and the
hourly power consumption in every season. Next, we present
an example of the calculation of the optimal storage
battery capacity in the case of priority utilization of the
photovoltaic electric power output for power consumption;
then, taking photovoltaic module capacity/price and storage
battery capacity as parameters, wecalculate the economic
improvement (merit) including the system cost for
© 2004 Wiley Periodicals, Inc.
Electrical Engineering in Japan, Vol. 147, No. 4, 2004
Translated from Denki Gakkai Ronbunshi, Vol. 123-B, No. 3, March 2003, pp. 402–411
20
“ordinal residences” (neither photovoltaic modules nor
storage batteries installed) and study the optimal combination
system, operation methods, and...