In 2013, Viessmann introduced their 5kWe ICE based M-5/13 manufactured
by subsidiary ESS, to supplement their micro CHP portfolio. It is
the smallest of their ICE based CHP range with electrical outputs up to
The engine is provided with a three way
catalytic converter to minimise emissions and Viessmann offer a range of
service options to ensure reliable long term operation, including remote
monitoring and control if required.
In addition to supplying engines to OEM
micro CHP manufacturers, such as EC Power, the Toyota Group are also
developing their own micro CHP products through subsidiaries DENSO
and Aisin Seiki.
The Aisin 6kWe unit has been available
for a number of years now in Japan and the USA and has, as expected
from a manufacturer with this pedigree, demonstrated reliable and
consistent performance at an acceptable, if not class leading level.
and manufactured by the BDR Thermea Group company Senertec GmbH, the DACHS is a
European manufactured mini-CHP unit. Operating reliably and successfully across Europe for
many years, the DACHS has achieved sales of over 8,000 units, mainly in Germany.
Its primary application is for small
hotels and apartment blocks (e.g. sheltered housing) where there is a
continuous electrical and thermal baseload. The resulting high
annual operating hours provide the substantial savings required to pay
back the relatively high capital cost.
However, it is physically too large and has too
high an electrical output to be suitable for anything but the largest
family homes, or those with swimming pools.
The Ecopower 1.5-4.7kWe micro CHP unit is based on the Marathon gas
The ability to modulate electrical power output to match demand is believed by its
developers to offer significant benefits over its competitors.
However, the high capital cost of this product
will require very high
running hours at full load in order to generate sufficient electricity
to recover the investment.
As for the Baxi Dachs unit, it is best
suited to small commercial premises and multi family apartment
Vaillant now offers a nominal 3.0kWe
(1.5-3.0kWe) and 4.7kWe (1.5-4.7kWe) version of the engine in
addition to the 1.0kWe Honda derivative.
Kirsch have developed a range of small CHP systems with electrical
outputs up to 50kW. Kirsch micro, as the nano,
is based on Briggs & Stratton ICE technology with a power output up to
Again, the electrical efficiency of 25% is
rather low compared with leading competitors.
With a range of stepped electrical outputs,
it can be configured to run either thermally led or optimised for
As with the nano, the
relatively high thermal output will confine this product to applications
with very substantial thermal demands, such as small hotels.
Despite the service requirement every 2,500
hours and a major overhaul at 20,000 hours, it is claimed to have a life
of up to 20 years, implying low expected annual run hours which,
as for the nano, make paybacks challenging.
It is currently only available in Germany.
The Proenvis prio 1.4, (again presumably
indicating its thermal and electrical outputs respectively) and
designated by its manufacturer as "mini-CHP" is another German ICE
based micro CHP product. It is capable of modulating its
electrical output between 2-3.8kWe.
At the same time it produces between
5.6-10.7kWt of heat with an overall efficiency of 92%, 24%
electrical and 68% thermal. Rather unusually this is lower than the
efficiency for their "nano-CHP" product and significantly lower than
for competitors in this power range.
The LPG fuelled variant has a slightly
higher overall efficiency of 95%, but electrical efficiency remains
at an unimpressive 25%.
The floor-mounted product is 70x98x98cm
with a weight of 350kg.
Fixed price service packages are offered
including the 5,000 hour oil and filter change.
Following the successful introduction of their mini CHP products in
2006, Yanmar added a 4kWe micro CHP to their range three years later.
As with the larger units, this packaged
unit is suitable for external location. Now available from
ENER.G in the UK.
Also in common with the larger engines,
the 4kWe product makes use of the advanced Miller Cycle.
The lean-burn system optimizes ignition timing and matches the
excess intake air; this reduces NOx and gives low-fuel consumption.
Furthermore, the adoption of the Miller
Cycle type engine creates even higher operating efficiency. The
engine offers a maintenance interval of 10,000 hours, which is one
of the industry's longest for a cogeneration gas engine.
Yet another German ICE based micro CHP unit! The growing
proliferation of products in this class may be more a reflection of
market pull (or, cynics might argue, Government subsidy) than any major
technical developments. A number of products have been launched
based on conventional ICE prime movers, focussing on mitigating the
limitations of the technology rather than seeking to address the
fundamentals through engine design.
In this case the Toyota industrial engine is
complemented by advanced acoustic isolation, catalytic converter and
remote diagnostics to pre-empt failure, providing anticipatory on-line
The unit is able to modulate power output up
to 5kWe and can be monitored either from the local interface or remotely
via the internet.
Founded in 2008, RMB Energie is a specialist
CHP manufacturer with products up to 20kWe output.