Evaluation of a multipurpose hybrid vehicle concept

The HOST project developed concept and prototype for an innovative low polluting modular transport mean suitable for the urban transport of people and goods. Main HOST commercial innovation is to use one vehicle for four different transport service in the 24 hours thus lowering the extra-cost of having a low polluting vehicle. HOST has been dimensioned to supply four different urban transport services: nocturne collective taxi, daytime car sharing, daytime freight collection and distribution and nocturne garbage collection. The user acceptance, energy and environmental and financial evaluation are reported in this paper. The user acceptance evaluation showed that HOST characteristics (transshipment capabilities, enhanced maneuverability and environmental concern) are interesting, but issues as the technological complexity and lack of infrastructures have to be resolved. The powertrain, a hybrid series, has considerably lower emissions levels than conventional vehicles while consumption is comparable for all the services but car-sharing in which HOST consumes more due to its higher weight. The financial evaluation shows that at the moment, to build the HOST powertrain, about 165 000 € are needed and a complete vehicle with also the cabin could cost about 290 000 €. To be financially competitive, the global cost of HOST should be between 220 000 and 230 000 €; 60 000€ less than the cost of the prototype.


Introduction
Today's European cities face many problems, and transport is one of the most relevant if not the most relevant. Mobility in cities gives problems of congestion, energy consumption, pollutant emissions, loss of green belts, occupancy of public spaces, and last but not least of health and safety.
Although passenger transport is always perceived to be the main cause of mobility related problems recent studies proved that freight transport impact is not negligible; from 30 to 40% of energy consumed for transport in cities is due to freight [1] and these percentages grow when certain pollutant, such as PM (Particulate Matters), are considered. Perceived level of comfort. The usefulness indicator quantifies how much HOST vehicle characteristics can help users to satisfy their needs and requests. The ease of use indicator measures how easy the user feels using the HOST vehicle would be in supplying the different services. The perception of safety measures how a user feels safe in the use of the HOST vehicle. The perceived level of comfort measures how comfortable the HOST vehicle is for its users. To measure these indicators, a demonstration of the use of the HOST prototype was required. Since the HOST prototype could not be transported in due time to the different sites and "tried" by the local stakeholders, the indicators to measure, as well as the method to measure them, were readdressed. The method chosen was to organize workshops in which the concept was presented, by means of the concept-and-styling-video produced as interim project result; and the prototype presented through the videotaped at the Bologna Motor Show by the national Italian TV news when it showed its maneuvering capabilities. The invited people were then asked to discuss the concept and then to fill in a questionnaire mostly to measure the usefulness of the vehicle, of its enhanced maneuverability and of the applicability of the new mobility concepts. The workshops, as well as the questionnaires, were slightly different in Italy and Sweden to reflect the local habitudes. Several questions were asked both in Stockholm and Rome and here results are compared. In both Rome and Stockholm most people think it is HOST vehicle can be used to supply more than one service. In both cities however 20% or more of the interviewees are openly against this possibility. In order to promote vehicles like HOST, knowing that not all agree with such concept, it could be possible to introduce it in a voluntary way: if anyone wants to adopt such concept can do it, while who does not agree can continue with the conventional technologies. The reasons of the skeptics are different for each city: the complexity of the system is the main reason in Stockholm: its weight, the difficulty to manage it etc.; in Rome instead the infrastructure is the main problem. There is cultural difference between the two cities: in Rome big changes as a deep modification in infrastructures are seen as impossible more than technological limits, the opposite happens in Stockholm. Enhanced maneuverability, the possibility to translate and rotate is positively seen wherever, but while in Stockholm there is more than a quarter of the interviewees that has little or no interest in such features, in Rome they are seen as the most desired feature of all. Such result may be due to the many problems in parking and the many small streets of Rome where these capabilities might be very useful.
In both cities, environmental concern is high and therefore any measure which might contribute to urban sustainability is well seen, however none of the operators fell the extra cost due to sustainability should fall upon the category.

HOST energy-environmental impact
To calculate the energy and the environmental impact of HOST, a set of experimental tests have been done at the JRC of ISPRA; the engine specifications, chosen from the experimental tests made on [4] with the following characteristics: 850 cc, (the Smart engine); Runs at 1800 rpm and with 16 kW of power. The tests, made at constant rpm show the following levels of consumption and emissions (Errore. L'origine riferimento non è stata trovata.). The methodology used in this section to evaluate the energy-environmental impact of HOST is the following.
The engine power requirement, for the driving cycles plus auxiliaries, for each service are known from [4] and reported in Table 2. The power requirement is dependent on the average speed of the missions, the weight and the auxiliaries onboard, so the hardest service is freight because of higher weight and, for some service, of the cooling system for refrigerated cargoes. The lightest is garbage due to the very low average speed. With such data the engine supplies more power than request for 3 of the 4services. For example for the car-sharing service the engine can be switched off for 37.5% of the time. The only service which requires the engine always on is freight. HOST makes daily all the services for 6 hours each and during the year the hours of work for each service are 2184. The kilometers made each year for every service are: taxi:30000; car-sharing: 30000; freight: 40000; garbage: 21000. For three services out of four, all but car-sharing, it is assumed that the 6 hours per day of each service are entirely used by the vehicle moving. Such assumption is not plausible for car-sharing. The percentage of time the vehicle is in use in this service is calculated as a product of the measured average speed car-sharing cars when in motion and overall on the day. The effective hours of daily use for HOST in car sharing are then 4.18 over the 6. To calculate consumption and emissions of the HOST vehicles in the different services the hourly consumption and emissions of the engine are multiplied by the percentage of time the vehicle is switched on and by the percentage of time the vehicle is in motion. Consumption and emissions levels calculated for the HOST vehicle are in Table 3. The consumption is not particularly good, but a series Hybrid is not the optimum strategy to minimize the consumption and CO2 production; however these values are close to those measurable for conventional vehicles. Also NOx seems to be high but real driving cycles require higher power values than those supplied during type approval procedure; however in the following section the results of an experimental campaign with a conventional diesel vehicle is reported and the emissions values of NOx are much higher.
HC and CO are very low due to the fact that HOST has a diesel engine that does not produce high levels of carbon monoxide and hydrocarbons.  To give a more accurate reference to consumption and emissions of car-sharing vehicles than the homologation data; road tests have been made on a Citroen C3 HDi 75 cv which is the kind of car often used in car-sharing services. The results of the on the road data collection campaign are reported in Table 4. Comparing the data in Table  4 with the first row of Table 3 it is clear that HOST would consume and emit much less than a conventional Diesel city car to supply the same service.
As for HOST measurements, the CO and HC for diesel vehicles are not a problem in terms of emissions produced, while NOx are more than 6 times higher the Euro IV limit although still less than the 20 times of the conventional diesel car tested. insurance costs (an averaged value is used to take account for the costs per year of insurance); fuel consumption (measured for all services with conventional Diesel vehicles and cost of Diesel fuel has been set to 1.1 € per liter); maintenance (10% of the purchase price has been used as yearly maintenance cost); driver's cost (the price for each hour of driver work is set to 20 €/hour). To take into account the deference between investments happening at the beginning and costs sustained operating the service a discount rate of 4% as been used.

Car Sharing
Following the user needs analysis a car-sharing vehicle is a city car with a an engine displacement between 1000 and 1500 cc, with specific power of about 5 kW/q and a length between 3.5 and 4 m. A typical vehicle could be a Renault Clio 1.5 dCi, a diesel vehicle that can be used to represent such service. It is a Euro IV vehicle of 1461 cm3 of displacement, 50 kW of maximum power at 4000 rpm and 120 g/km of CO2 during the type approval procedure. To perform a financial evaluation of the carsharing service made from this vehicle the following data are considered: it is used for 40000 km/year; the purchase price is about 15000 €; the insurance is about 1500 €/year; the consumption is 11.3 km/l as measured for the Citroen C3 being car sharing the sole service not requiring drivers no driver costs have been considered. With the above hypotheses the vehicle costs about 0.23 €/km or 7054 €/year. Such figure is stable changing car brand or model it just slightly increases with the vehicle size; bigger cars can reach up to 0.35 €/km (this is the case for a Fiat Multipla).

Nocturne Collective Taxi
The vehicle used to calculate the costs per km for the nocturne collective taxi, a light duty vehicle. A Fiat Ducato Panorama with the following characteristics was chosen.
2.2 dm3 engine displacement, 100 cv maximum power, diesel fueled, Euro IV; 9 passengers, maximum weight 3000 kg (drivable with "B" driving license, the same as cars); length 5450 mm; width 2050 mm. To calculate the vehicle costs for running a nocturne collective taxi service the following data are used.
The vehicle is used during nights from 20 to 2 a.m. (6 hours /day). It is used for 30000 km/year. The purchase price is about 30000 €.
The insurance is about 1800 €/year. The driver's cost is 20 €/hour. The costs per km of this vehicle for nocturne collective taxi is about 1.90 €/km. The largest portion of such cost is the driver who costs more than 1.4 €/km while all the others together are about 0.50 €/km.

Garbage Collection
To calculate the costs per km of the door-to-door garbage collection service, the data collected in Rome during the HOST user needs analysis are used. This service is supplied with Iveco Daily light duty vehicles equipped with caissons to collect garbage.
The Iveco Daily used for this service has the following characteristics: 2.3 dm3 engine displacement, 100 kW maximum power, diesel fueled, Euro IV; maximum weight 3500 kg (drivable with "B" driving license, the same as cars); wheelbase 3000 mm. To calculate the costs per km of the door-to-door garbage collection service the following data are used.
The vehicle works 12 hours for 5 days (Monday to Friday) and 6 hours on Saturday. It is used for 21000 km/year. The purchase price, comprehensive of the tool to collect the garbage, is about 50000 €.
The insurance is about 1800 €/year. The driver's cost is 20 €/hour. The first thing to say about this service is that the vehicle run at very low speed and, even if the service is active more hours daily than the others, the mileage of the vehicles is very low. The depreciation term for example is 0.35 €/km, higher than the same term for collective taxi that is 0.14, but the big difference is the cost of the driver: 3.26 €/km. The total kilometric cost of this service is then about 4 €/km.

Freight distribution
Freight delivery service is the one to be thoroughly changed to have Host vehicles adopted. Host has not been designed to run out of the urban environment while today the delivery platforms from which trucks leave for their delivery rounds are out of the city. The Host scenario would therefore imply one more passage; the freight should leave the outer urban area with a shuttle train and being transshipped on Host vehicles in a rail terminal inside the city. The implementation of such scenario is complex not just because of costs but because an agreement between several operators, as well as the appropriate infrastructures need to be found. Only the intervention of the authorities, putting in place regulations which practically oblige private actors to re-organize their delivery services, could foster such model. Leaving the evaluation of this complex scenario to other studies here the interest is focused on comparing vehicle costs. It is therefore assumed such new freight delivery scenario to be in place either with conventional or Host vehicles. Vehicles gross weight in this new scenario would be 60 q to allow a load of 40 q or more. The Iveco EuroCargo 60E14, with 60 q of maximum weight at full load and 140 cv of maximum power has been chosen as the conventional vehicle to compare Host cost's with. To evaluate the costs of the freight distribution service, a table from [6] was used. This table reports all the costs for freight transport for an Iveco EuroCargo 60E14 varying the annual mileage. The only term to specify to read this table is the km per year made by this service and the only modification done is to neglect the fees for highways because the vehicle is used in urban environment. For the service analyzed on average each vehicle run 40 000 km/year and then the vehicle cost is 1.446 €/km.

Cross comparison and financial evaluation
Estimating the cost of Host vehicles, assuming they will be produced in small series, is not a simple task. Clearly the cost of the prototype reported in the first subsection of this section is too high to compare it with vehicle produced in series.
In this subsection, using the same relations for the financial evaluation of the 4 services made with conventional vehicles, a cost per km curve is built varying the purchase cost. This allows finding the breakeven cost under which using Host for the four services would cost less than using four different conventional vehicles. In the present analysis the costs of the cabins are included on the purchase cost, but all the other additional costs (to change the cabin etc.) are not considered. Moreover, also some of the benefits of adopting such technology are not considered in this work, and also some of them should be showed to advantage in the perspective of a ecocompatible transport; at the moment a vehicle with lower emissions levels has no advantages in financial terms, and also the fact that HOST does not park is an advantage in that sense. The total kilometric cost of all the services supplied with conventional vehicles calculated in the previous subsection is summed up in Table 6. The total cost, supplying the four services is 1.698 €/km and the kilometers made by the four vehicles all together are 121 000 each year. To calculate the total kilometrical cost of HOST, the following hypotheses were used. HOST is able to make all the services made today with the conventional vehicles; in practice one HOST make the job of 4 vehicles. It is able then to make the sum of all the kilometers made: 121000 km/year. HOST is in use 24 hours a day; 6 hours for every service.

Con
The